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Fortinet FortiOS

product · product:fortinet-fortios single-source

Coverage
6
first 2026-06-18 → last 2026-10-16
Latest activity
2026-10-16
Unit 42: a memory-resident FortiGate implant rides an exploited FortiOS flaw that has no fix on 7.2, 7.0 and…
Peak priority
high
4 high · 2 notable
Targets
public-sector
sectors: public-sector, telco, finance · regions: europe
Sources cited
25
15 hosts

Action items (6)

Do-now tasks recorded on the entries about Fortinet FortiOS, newest first. Check the date before acting on an older one.

  • Audit every internet-facing FortiGate for administrator accounts and REST API keys nobody created, then terminate all administrator and VPN sessions and reset every administrator and VPN password.
    2026-06-18FBI and Secret Service: FortiBleed is still active…
  • Patch every internet-facing FortiGate/FortiSwitchManager to the fixed builds now, and on any device that exposed CAPWAP (UDP 5246) to an untrusted network before patching, rotate VPN PSKs, SSL-VPN and LDAP bind credentials and admin passwords rather than relying on the patch alone; PivotC2's autonomous mode is built to harvest exactly those credential stores.
    2026-09-10CVE-2025-25249
  • Search authentication-server change history on every VDI, SSL-VPN and SSO portal for edits to authentication-processing files, and re-validate that a repeated OTP value cannot authenticate; a password reset and an MFA re-enrolment do not remove this backdoor.
    2026-08-11CVE-2024-55591 +1
  • If a Linux host has been encrypted with the .GNRA extension, preserve the encrypted files, their timestamps and the system logs before any rebuild: the advisory states the keys can be reconstructed from file timestamps, and reimaging destroys the recovery path.
    2026-08-11CVE-2024-55591 +1
  • Enumerate every FortiGate that was running SSL-VPN while exposed to an earlier root-filesystem FortiOS vulnerability and check the SSL-VPN language-file directories for symbolic links pointing outside the user filesystem; do this regardless of when the device was patched, because this flaw specifically defeats the fix that was supposed to close that persistence path.
    2026-07-28CVE-2025-68686
1 older action item
  • Move FortiOS 7.2, 7.0 and 6.4 devices onto a supported branch: those trains are affected in all versions and have no fixed build, so upgrading within the branch does not remediate.
    2026-07-28CVE-2025-68686

Defender insights

What each entry about Fortinet FortiOS tells a defender to do, newest first.

2026-10-16NOTABLEexploitedUnit 42: a memory-resident FortiGate implant rides an exploited FortiOS flaw that has no fix on 7.2, 7.0 and 6.4

Exposure · triage · detection

2026-06-18HIGHexploitedFBI and Secret Service: FortiBleed is still active, locks admins out of FortiGates and feeds ransomware affiliates

Exposure · detection

2026-09-10HIGHexploitedA months-old Fortinet CAPWAP bug reaches CISA KEV alongside an AI-assisted post-exploitation RAT built specifically for FortiGate

Triage

2026-09-07NOTABLEInsikt Group: the same six-tool stack followed thirteen unrelated CVEs into Exchange, SharePoint, FortiOS, Cisco IOS XE, F5 BIG-IP, GeoServer and Apache Shiro

2026-08-11HIGHexploitedSix agencies publish the Gunra RaaS playbook, edge exploitation, an OTP-value MFA backdoor, and a recoverable Linux key

Triage · detection

Story timeline

  1. 2026-10-16PEERSTITCH: a memory-resident FortiGate implant installed through the FortiOS CLI path traversal CVE-2025-61624, which Fortinet lists as exploited and leaves unfixed on FortiOS 7.2, 7.0 and 6.4, after a FortiManager compromise exposed the configurations of 500+ firewalls
    active-threatsUnit 42: a memory-resident FortiGate implant rides an exploited FortiOS flaw that has no fix on 7.2, 7.0 and 6.4
  2. 2026-09-10CVE-2025-25249, Fortinet FortiOS/FortiSwitchManager: unauthenticated CAPWAP heap overflow added to CISA KEV, actively exploited since July via the PivotC2 RAT
    trending-vulnerabilitiesA months-old Fortinet CAPWAP bug reaches CISA KEV alongside an AI-assisted post-exploitation RAT built specifically for FortiGate
  3. 2026-09-07Recorded Future's H1 2026 Malware and Vulnerability Trends: two clusters reuse an identical post-exploitation tool stack across thirteen and ten unrelated initial CVEs
    researchInsikt Group: the same six-tool stack followed thirteen unrelated CVEs into Exchange, SharePoint, FortiOS, Cisco IOS XE, F5 BIG-IP, GeoServer and Apache Shiro
  4. 2026-08-11Gunra ransomware-as-a-service: a joint six-agency advisory documents FortiOS edge exploitation, a persistent MFA backdoor built from one fixed OTP value, and a Linux encryptor whose keys can be reconstructed
    deep-diveSix agencies publish the Gunra RaaS playbook, edge exploitation, an OTP-value MFA backdoor, and a recoverable Linux key
  5. 2026-07-28CVE-2025-68686, FortiOS SSL-VPN: the fix for the symlink-persistence technique is itself bypassable, and CISA now lists it as exploited
    trending-vulnerabilitiesCISA KEV-lists a FortiOS flaw that defeats Fortinet's own fix for SSL-VPN symlink persistence
  6. 2026-06-18FortiBleed: an active credential-compromise campaign against internet-facing FortiGate firewalls, now locking administrators out and supplying ransomware affiliates
    active-threatsFBI and Secret Service: FortiBleed is still active, locks admins out of FortiGates and feeds ransomware affiliates
ATT&CK techniques (63 across 15 tactics)

63 techniques observed across 6 entries about this entity, derived from entry metadata and body evidence, never asserted without a published entry behind it · pinned to MITRE ATT&CK v20.0 · compare on the matrix · Navigator layer (JSON)

  • ReconnaissanceActive Scanning
  • Resource DevelopmentAcquire Infrastructure
  • Initial AccessValid Accounts · Valid Accounts: Default Accounts · Valid Accounts: Domain Accounts · External Remote Services · Exploit Public-Facing Application
  • ExecutionWindows Management Instrumentation · Command and Scripting Interpreter: PowerShell · Command and Scripting Interpreter: Windows Command Shell · Command and Scripting Interpreter: Unix Shell · Command and Scripting Interpreter: JavaScript · Native API
  • PersistenceValid Accounts · Valid Accounts: Default Accounts · Valid Accounts: Domain Accounts · Account Manipulation · External Remote Services · Create Account: Local Account · Server Software Component: Web Shell · Modify Authentication Process: Multi-Factor Authentication
  • Privilege EscalationProcess Injection: Portable Executable Injection · Process Injection: Ptrace System Calls · Exploitation for Privilege Escalation · Valid Accounts · Valid Accounts: Default Accounts · Valid Accounts: Domain Accounts · Account Manipulation
  • StealthObfuscated Files or Information · Process Injection: Portable Executable Injection · Process Injection: Ptrace System Calls · Indicator Removal · Indicator Removal: Clear Command History · Valid Accounts · Valid Accounts: Default Accounts · Valid Accounts: Domain Accounts · Exploitation for Stealth · Debugger Evasion · Delay Execution · Selective Exclusion
  • Defense ImpairmentModify Authentication Process: Multi-Factor Authentication · Disable or Modify Tools · Disable or Modify Tools: Clear Linux or Mac System Logs
  • Credential AccessOS Credential Dumping · OS Credential Dumping: NTDS · Network Sniffing · Brute Force: Password Cracking · Brute Force: Password Spraying · Brute Force: Credential Stuffing · Steal Web Session Cookie · Unsecured Credentials: Credentials In Files · Credentials from Password Stores · Modify Authentication Process: Multi-Factor Authentication
  • DiscoveryNetwork Sniffing · Network Service Discovery · System Network Connections Discovery · System Information Discovery · File and Directory Discovery · Account Discovery · Debugger Evasion
  • Lateral MovementRemote Services: Remote Desktop Protocol · Remote Services: SMB/Windows Admin Shares · Use Alternate Authentication Material: Pass the Hash · Use Alternate Authentication Material: Pass the Ticket
  • CollectionData from Local System · Email Collection · Data from Cloud Storage · Archive Collected Data
  • Command and ControlApplication Layer Protocol: Web Protocols · Proxy · Ingress Tool Transfer · Protocol Tunneling
  • ExfiltrationExfiltration Over C2 Channel · Exfiltration Over Alternative Protocol · Exfiltration Over Web Service · Exfiltration Over Web Service: Exfiltration to Cloud Storage
  • ImpactData Encrypted for Impact · Inhibit System Recovery · Account Access Removal · Financial Theft

Reconnaissance TA0043

T1595Active Scanning×1

Adversaries may execute active reconnaissance scans to gather information that can be used during targeting. Active scans are those where the adversary probes victim infrastructure via network traffic, as opposed to other forms of reconnaissance that do not involve direct interaction.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

Resource Development TA0042

T1583Acquire Infrastructure×1

Adversaries may buy, lease, rent, or obtain infrastructure that can be used during targeting. A wide variety of infrastructure exists for hosting and orchestrating adversary operations. Infrastructure solutions include physical or cloud servers, domains, and third-party web services. Some infrastructure providers offer free trial periods, enabling infrastructure acquisition at limited to no cost. Additionally, botnets are available for rent or purchase.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

Initial Access TA0001

T1078Valid Accounts×2

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1078.001Valid Accounts: Default Accounts×1

Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems. Default accounts also include default factory/provider set accounts on other types of systems, software, or devices, including the root user account in AWS, the root user account in ESXi, and the default service account in Kubernetes.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1078.002Valid Accounts: Domain Accounts×1

Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1133External Remote Services×3

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1190Exploit Public-Facing Application×5

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network. The weakness in the system can be a software bug, a temporary glitch, or a misconfiguration.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · 2026-07-28/cve-2025-68686-fortios-ssl-vpn-symlink-persistence-kev · ATT&CK page ↗

Execution TA0002

T1047Windows Management Instrumentation×1

Adversaries may abuse Windows Management Instrumentation (WMI) to execute malicious commands and payloads. WMI is designed for programmers and is the infrastructure for management data and operations on Windows systems. WMI is an administration feature that provides a uniform environment to access Windows system components.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1059.001Command and Scripting Interpreter: PowerShell×2

Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system. PowerShell can also be installed on Linux and macOS. Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the <code>Start-Process</code> cmdlet which can be used to run an executable and the <code>Invoke-Command</code> cmdlet which runs a command locally or on a remote computer (though administrator permissions are required to use PowerShell to connect to remote systems).

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · ATT&CK page ↗

T1059.003Command and Scripting Interpreter: Windows Command Shell×2

Adversaries may abuse the Windows command shell for execution. The Windows command shell (cmd) is the primary command prompt on Windows systems. The Windows command prompt can be used to control almost any aspect of a system, with various permission levels required for different subsets of commands. The command prompt can be invoked remotely via Remote Services such as SSH.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1059.004Command and Scripting Interpreter: Unix Shell×1

Adversaries may abuse Unix shell commands and scripts for execution. Unix shells are the primary command prompt on Linux, macOS, and ESXi systems, though many variations of the Unix shell exist (e.g. sh, ash, bash, zsh, etc.) depending on the specific OS or distribution. Unix shells can control every aspect of a system, with certain commands requiring elevated privileges.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · ATT&CK page ↗

T1059.007Command and Scripting Interpreter: JavaScript×1

Adversaries may abuse various implementations of JavaScript for execution. JavaScript (JS) is a platform-independent scripting language (compiled just-in-time at runtime) commonly associated with scripts in webpages, though JS can be executed in runtime environments outside the browser.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

T1106Native API×1

Adversaries may interact with the native OS application programming interface (API) to execute behaviors. Native APIs provide a controlled means of calling low-level OS services within the kernel, such as those involving hardware/devices, memory, and processes. These native APIs are leveraged by the OS during system boot (when other system components are not yet initialized) as well as carrying out tasks and requests during routine operations.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Persistence TA0003

T1078Valid Accounts×2

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1078.001Valid Accounts: Default Accounts×1

Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems. Default accounts also include default factory/provider set accounts on other types of systems, software, or devices, including the root user account in AWS, the root user account in ESXi, and the default service account in Kubernetes.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1078.002Valid Accounts: Domain Accounts×1

Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1098Account Manipulation×1

Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups. These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1133External Remote Services×3

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1136.001Create Account: Local Account×1

Adversaries may create a local account to maintain access to victim systems. Local accounts are those configured by an organization for use by users, remote support, services, or for administration on a single system or service.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1505.003Server Software Component: Web Shell×1

Adversaries may backdoor web servers with web shells to establish persistent access to systems. A Web shell is a Web script that is placed on an openly accessible Web server to allow an adversary to access the Web server as a gateway into a network. A Web shell may provide a set of functions to execute or a command-line interface on the system that hosts the Web server.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · ATT&CK page ↗

T1556.006Modify Authentication Process: Multi-Factor Authentication×1

Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Privilege Escalation TA0004

T1055.002Process Injection: Portable Executable Injection×1

Adversaries may inject portable executables (PE) into processes in order to evade process-based defenses as well as possibly elevate privileges. PE injection is a method of executing arbitrary code in the address space of a separate live process.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1055.008Process Injection: Ptrace System Calls×1

Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

T1068Exploitation for Privilege Escalation×1

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Security constructs such as permission levels will often hinder access to information and use of certain techniques, so adversaries will likely need to perform privilege escalation to include use of software exploitation to circumvent those restrictions.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

T1078Valid Accounts×2

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1078.001Valid Accounts: Default Accounts×1

Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems. Default accounts also include default factory/provider set accounts on other types of systems, software, or devices, including the root user account in AWS, the root user account in ESXi, and the default service account in Kubernetes.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1078.002Valid Accounts: Domain Accounts×1

Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1098Account Manipulation×1

Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups. These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Stealth TA0005

T1027Obfuscated Files or Information×1

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1055.002Process Injection: Portable Executable Injection×1

Adversaries may inject portable executables (PE) into processes in order to evade process-based defenses as well as possibly elevate privileges. PE injection is a method of executing arbitrary code in the address space of a separate live process.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1055.008Process Injection: Ptrace System Calls×1

Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

T1070Indicator Removal×1

Adversaries may selectively delete or modify artifacts generated to reduce indications of their presence and blend in with legitimate activity. Rather than broadly removing evidence, adversaries may target specific artifacts that appear anomalous or are likely to draw scrutiny, while leaving sufficient data intact to maintain the appearance of normal system behavior.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

T1070.003Indicator Removal: Clear Command History×1

In addition to clearing system logs, an adversary may clear the command history of a compromised account to conceal the actions undertaken during an intrusion. Various command interpreters keep track of the commands users type in their terminal so that users can retrace what they've done.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1078Valid Accounts×2

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1078.001Valid Accounts: Default Accounts×1

Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems. Default accounts also include default factory/provider set accounts on other types of systems, software, or devices, including the root user account in AWS, the root user account in ESXi, and the default service account in Kubernetes.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1078.002Valid Accounts: Domain Accounts×1

Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1211Exploitation for Stealth×1

Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.

Evidence: 2026-07-28/cve-2025-68686-fortios-ssl-vpn-symlink-persistence-kev · ATT&CK page ↗

T1622Debugger Evasion×1

Adversaries may employ various means to detect and avoid debuggers. Debuggers are typically used by defenders to trace and/or analyze the execution of potential malware payloads.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1678Delay Execution×1

Adversaries may employ various time-based methods to evade detection and analysis. These techniques often exploit system clocks, delays, or timing mechanisms to obscure malicious activity, blend in with benign activity, and avoid scrutiny. Adversaries can perform this behavior within virtualization/sandbox environments or natively on host systems.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1679Selective Exclusion×1

Adversaries may intentionally exclude certain files, folders, directories, file types, or system components from encryption or tampering during a ransomware or malicious payload execution. Some file extensions that adversaries may avoid encrypting include `.dll`, `.exe`, and `.lnk`.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Defense Impairment TA0112

T1556.006Modify Authentication Process: Multi-Factor Authentication×1

Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1685Disable or Modify Tools×1

Adversaries may disable, degrade, or tamper with security tools or applications (e.g., endpoint detection and response (EDR) tools, intrusion detection systems (IDS), antivirus, logging agents, sensors, etc.) to impair or reduce visibility of defensive capabilities. This may include stopping specific services, killing processes, modifying or deleting tool configuration files and Registry keys, or preventing tools from updating. This may also include impairing defenses more broadly by disrupting preventative, detection, and response mechanisms across host, network, and cloud environments.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1685.006Disable or Modify Tools: Clear Linux or Mac System Logs×1

Adversaries may clear system logs to hide evidence of an intrusion. macOS and Linux both keep track of system or user-initiated actions via system logs. The majority of native system logging is stored under the `/var/log/` directory. Subfolders in this directory categorize logs by their related functions, such as:

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · ATT&CK page ↗

Credential Access TA0006

T1003OS Credential Dumping×2

Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password. Credentials can be obtained from OS caches, memory, or structures. Credentials can then be used to perform Lateral Movement and access restricted information.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1003.003OS Credential Dumping: NTDS×1

Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights. By default, the NTDS file (NTDS.dit) is located in <code>%SystemRoot%\NTDS\Ntds.dit</code> of a domain controller.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1040Network Sniffing×2

Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1110.002Brute Force: Password Cracking×1

Adversaries may use password cracking to attempt to recover usable credentials, such as plaintext passwords, when credential material such as password hashes are obtained. OS Credential Dumping can be used to obtain password hashes, this may only get an adversary so far when Pass the Hash is not an option. Further, adversaries may leverage Data from Configuration Repository in order to obtain hashed credentials for network devices.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1110.003Brute Force: Password Spraying×1

Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1110.004Brute Force: Credential Stuffing×1

Adversaries may use credentials obtained from breach dumps of unrelated accounts to gain access to target accounts through credential overlap. Occasionally, large numbers of username and password pairs are dumped online when a website or service is compromised and the user account credentials accessed. The information may be useful to an adversary attempting to compromise accounts by taking advantage of the tendency for users to use the same passwords across personal and business accounts.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1539Steal Web Session Cookie×1

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials. Web applications and services often use session cookies as an authentication token after a user has authenticated to a website.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1552.001Unsecured Credentials: Credentials In Files×2

Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials. These can be files created by users to store their own credentials, shared credential stores for a group of individuals, configuration files containing passwords for a system or service, or source code/binary files containing embedded passwords.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1555Credentials from Password Stores×1

Adversaries may search for common password storage locations to obtain user credentials. Passwords are stored in several places on a system, depending on the operating system or application holding the credentials. There are also specific applications and services that store passwords to make them easier for users to manage and maintain, such as password managers and cloud secrets vaults. Once credentials are obtained, they can be used to perform lateral movement and access restricted information.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1556.006Modify Authentication Process: Multi-Factor Authentication×1

Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Discovery TA0007

T1040Network Sniffing×2

Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.

Evidence: 2026-10-16/peerstitch-fortigate-implant-cve-2025-61624-fortimanager · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1046Network Service Discovery×1

Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation. Common methods to acquire this information include port, vulnerability, and/or wordlist scans using tools that are brought onto a system.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1049System Network Connections Discovery×1

Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1082System Information Discovery×1

An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture. Adversaries may use this information to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions. This behavior is distinct from Local Storage Discovery which is an adversary's discovery of local drive, disks and/or volumes.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · ATT&CK page ↗

T1083File and Directory Discovery×1

Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1087Account Discovery×1

Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment. This information can help adversaries determine which accounts exist, which can aid in follow-on behavior such as brute-forcing, spear-phishing attacks, or account takeovers (e.g., Valid Accounts).

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1622Debugger Evasion×1

Adversaries may employ various means to detect and avoid debuggers. Debuggers are typically used by defenders to trace and/or analyze the execution of potential malware payloads.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Lateral Movement TA0008

T1021.001Remote Services: Remote Desktop Protocol×2

Adversaries may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1021.002Remote Services: SMB/Windows Admin Shares×1

Adversaries may use Valid Accounts to interact with a remote network share using Server Message Block (SMB). The adversary may then perform actions as the logged-on user.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1550.002Use Alternate Authentication Material: Pass the Hash×1

Adversaries may “pass the hash” using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1550.003Use Alternate Authentication Material: Pass the Ticket×1

Adversaries may “pass the ticket” using stolen Kerberos tickets to move laterally within an environment, bypassing normal system access controls. Pass the ticket (PtT) is a method of authenticating to a system using Kerberos tickets without having access to an account's password. Kerberos authentication can be used as the first step to lateral movement to a remote system.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Collection TA0009

T1005Data from Local System×3

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · 2026-07-28/cve-2025-68686-fortios-ssl-vpn-symlink-persistence-kev · ATT&CK page ↗

T1114Email Collection×1

Adversaries may target user email to collect sensitive information. Emails may contain sensitive data, including trade secrets or personal information, that can prove valuable to adversaries. Emails may also contain details of ongoing incident response operations, which may allow adversaries to adjust their techniques in order to maintain persistence or evade defenses. Adversaries can collect or forward email from mail servers or clients.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1530Data from Cloud Storage×1

Adversaries may access data from cloud storage.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1560Archive Collected Data×1

An adversary may compress and/or encrypt data that is collected prior to exfiltration. Compressing the data can help to obfuscate the collected data and minimize the amount of data sent over the network. Encryption can be used to hide information that is being exfiltrated from detection or make exfiltration less conspicuous upon inspection by a defender.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Command and Control TA0011

T1071.001Application Layer Protocol: Web Protocols×2

Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · ATT&CK page ↗

T1090Proxy×1

Adversaries may use a connection proxy to direct network traffic between systems or act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including HTRAN, ZXProxy, and ZXPortMap. Adversaries use these types of proxies to manage command and control communications, reduce the number of simultaneous outbound network connections, provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between victims to avoid suspicion. Adversaries may chain together multiple proxies to further disguise the source of malicious traffic.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

T1105Ingress Tool Transfer×2

Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer).

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1572Protocol Tunneling×1

Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection/network filtering and/or enable access to otherwise unreachable systems. Tunneling involves explicitly encapsulating a protocol within another. This behavior may conceal malicious traffic by blending in with existing traffic and/or provide an outer layer of encryption (similar to a VPN). Tunneling could also enable routing of network packets that would otherwise not reach their intended destination, such as SMB, RDP, or other traffic that would be filtered by network appliances or not routed over the Internet.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Exfiltration TA0010

T1041Exfiltration Over C2 Channel×2

Adversaries may steal data by exfiltrating it over an existing command and control channel. Stolen data is encoded into the normal communications channel using the same protocol as command and control communications.

Evidence: 2026-09-07/recordedfuture-h1-2026-tool-stack-reuse · 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1048Exfiltration Over Alternative Protocol×1

Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1567Exfiltration Over Web Service×1

Adversaries may use an existing, legitimate external Web service to exfiltrate data rather than their primary command and control channel. Popular Web services acting as an exfiltration mechanism may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to compromise. Firewall rules may also already exist to permit traffic to these services.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1567.002Exfiltration Over Web Service: Exfiltration to Cloud Storage×1

Adversaries may exfiltrate data to a cloud storage service rather than over their primary command and control channel. Cloud storage services allow for the storage, edit, and retrieval of data from a remote cloud storage server over the Internet.

Evidence: 2026-09-10/cve-2025-25249-fortinet-fortios-capwap-pivotc2-rat · ATT&CK page ↗

Impact TA0040

T1486Data Encrypted for Impact×1

Adversaries may encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources. They can attempt to render stored data inaccessible by encrypting files or data on local and remote drives and withholding access to a decryption key. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key (ransomware) or to render data permanently inaccessible in cases where the key is not saved or transmitted.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1490Inhibit System Recovery×1

Adversaries may delete or remove built-in data and turn off services designed to aid in the recovery of a corrupted system to prevent recovery. This may deny access to available backups and recovery options.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

T1531Account Access Removal×1

Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users. Accounts may be deleted, locked, or manipulated (ex: changed credentials, revoked permissions for SaaS platforms such as Sharepoint) to remove access to accounts. Adversaries may also subsequently log off and/or perform a System Shutdown/Reboot to set malicious changes into place.

Evidence: 2026-06-18/fortibleed-73-932-internet-facing-fortigate-devices-exposed · ATT&CK page ↗

T1657Financial Theft×1

Adversaries may steal monetary resources from targets through extortion, social engineering, technical theft, or other methods aimed at their own financial gain at the expense of the availability of these resources for victims. Financial theft is the ultimate objective of several popular campaign types including extortion by ransomware, business email compromise (BEC) and fraud, "pig butchering," bank hacking, and exploiting cryptocurrency networks.

Evidence: 2026-08-11/gunra-raas-fortios-mfa-backdoor-linux-prng-recoverable · ATT&CK page ↗

Entries about Fortinet FortiOS (6)

2026-10-16 · view entry permalink →

NOTABLECVE-2025-61624exploitedNATOB2

PEERSTITCH: a memory-resident FortiGate implant installed through the FortiOS CLI path traversal CVE-2025-61624, which Fortinet lists as exploited and leaves unfixed on FortiOS 7.2, 7.0 and 6.4, after a FortiManager compromise exposed the configurations of 500+ firewalls

Unit 42 investigated a September 2024 intrusion at a telecommunications organization, tracked as cluster CL-STA-0954, that began with CVE-2024-47575 against a centralized FortiManager appliance: the attackers registered a rogue virtual FortiGate, then exfiltrated an archive with the running configurations, cryptographic material and database files of more than 500 managed FortiGate firewalls (Unit 42, 2026-10-14). Unit 42 recovered the configurations' reversible-ciphertext credentials by brute force; the attackers later logged in over SSL VPN with legitimate credentials and pushed packet-capture settings to downstream firewalls (Unit 42, 2026-10-14).

For root they used CVE-2025-61624, a path traversal in the FortiOS CLI system.auto-script engine that lets an authenticated administrative account read and write arbitrary files as root (Unit 42, 2026-10-14). That installed PEERSTITCH, an ARM64 injector that attaches with ptrace to the logging daemon miglogd and the IPsec daemon iked, allocates a 16 KB read-write-execute region, NOP-patches three fixed offsets and links the daemons through /proc memory so that tagged VPN sessions skip default FortiOS validation; it leaves no persistent binary on disk, opens no listening port and makes no outbound connection of its own (Unit 42, 2026-10-14). Command and control ran through the firewall's own Apache mod_md ACME module, whose DNS-01 challenge handler executes Node.js with parameters from an attacker-run ACME server and so opens a reverse shell (Unit 42, 2026-10-14).

Fortinet's advisory FG-IR-26-122 of 2026-04-14 covers the CLI path traversal in FortiOS, FortiPAM, FortiProxy and FortiSwitchManager, lists it as known exploited, and for FortiOS gives fixes only in 7.6.5 and 7.4.10, telling users of 7.2, 7.0 and 6.4 to migrate to a fixed release (Fortinet, 2026-04-14).

Triage: legitimate FortiManager work also creates and deletes auto-scripts and adds devices; the report's signals are ../ in an auto-script name, a device registered from outside the management network, and accounts that match no administrator or tenant the organization created.

PEERSTITCH leaves no persistent binary on disk, opens no listening ports and initiates no outbound network connections.

The vulnerability allows an authenticated administrative account to read and write arbitrary files as root via path traversal in the FortiOS CLI system.auto-script engine.

the attackers exfiltrated an archive containing running configurations, cryptographic material and database files containing information about more than 500 managed FortiGate firewalls

The cryptographic trust material governing the platform's relationship with every managed device leaves with the attacker and remains valid until it is rotated.

Palo Alto Networks Unit 42 2026-10-14

Builds on: FBI and Secret Service: FortiBleed is still active, locks admins out of FortiGates and feeds…

threat16 Oct 04:22Zsingle-sourceOpen finding →

2026-06-18 · view entry permalink →

HIGHexploitedupdatedNATOA1

FortiBleed: an active credential-compromise campaign against internet-facing FortiGate firewalls, now locking administrators out and supplying ransomware affiliates

A dataset branded "FortiBleed" was reported on 2026-06-18, containing 73,932 unique FortiGate management URLs, roughly 75,000 devices across 194 countries and 21,632 domains, paired with valid VPN and administrative credentials (BleepingComputer, 2026-06-18). Fortinet's position is that this is not a new Fortinet vulnerability: it believes threat actors are reusing credentials from previous incidents and using brute force against devices with weak password hygiene and no multi-factor authentication (Fortinet PSIRT, 2026-06-19). BleepingComputer reports researcher Bob Diachenko's claim that a Russian-speaking multi-operator group harvested the credentials, cracked intercepted SSL VPN hashes on a 45-GPU cluster and moved laterally into internal Active Directory environments, with several organisations fully compromised; Diachenko says he drew this from files the attackers left exposed on the same server (BleepingComputer, 2026-06-18); Arctic Wolf is separately tracking the FortiBleed campaign's reach across 194 countries (Arctic Wolf, 2026-06-17). The technique class is valid-account abuse following credential access, not exploitation of a fresh CVE.

which abuses FortiOS's built-in diagnose sniffer packet functionality to capture authentication traffic traversing compromised FortiGate devices

BleepingComputer

we believe the activity involves threat actors reusing credentials from previous incidents and employing brute-force techniques against devices with weak password hygiene and no multi-factor authentication (MFA)

SecurityWeek

The FBI says that in some incidents, the threat actor creates administrator accounts and uses their privileges to delete existing admin accounts or change their passwords, denying victims access to their devices.

Some groups benefiting from this are INC/Lynx ransomware and Payload ransomware.

BleepingComputer
Updaterun 2026-06-20-4cfd00efregionssourcestagsbody

The FortiBleed SSL VPN credential-harvesting campaign has grown from the 73,932 internet-facing FortiGate devices reported on 2026-06-18 to 86,644 confirmed compromised credentials across 194 countries, and CISA has published a hardening alert (SecurityWeek, 2026-06-19; CISA, 2026-06-18).

The new detail is methodology and impact, as researcher Bob Diachenko claims it: the operators intercept SSL VPN authentication, crack the hashes on a 45-GPU cluster managed through Hashtopolis and pivot into internal Active Directory environments (SecurityWeek, 2026-06-19; BleepingComputer, 2026-06-18). CISA's alert urges terminating active sessions and resetting credentials, storing administrator logins with PBKDF2, reviewing logs, enabling phishing-resistant MFA and locking down management access (SecurityWeek, 2026-06-19). Fortinet advises checking for unexpected administrator access from an unknown IP and reviewing domain controller logs for lateral movement (Fortinet PSIRT, 2026-06-19).

Updaterun 2026-06-23-165387f6evidencesectorssourcesbody

New analysis published 2026-06-22 gives a more detailed description of the tool chain behind the FortiBleed credential-harvesting campaign. SOCRadar's report, as BleepingComputer describes it, alleges a purpose-built Golang tool, FortigateSniffer, that abuses FortiOS's built-in diagnose sniffer packet command to capture authentication traffic on a compromised FortiGate, with a component named SNIFTRAN reconstructing the captured traffic into PCAP files and a Python toolkit extracting cleartext credentials, password hashes, Kerberos tickets and NTLM authentication material from them, across 24 protocols (BleepingComputer, 2026-06-22).

Fortinet's PSIRT response confirms the campaign uses no new vulnerability: it reuses credentials from the previously-disclosed CVE-2026-24858, CVE-2025-59718 and CVE-2025-59719 plus brute force against devices lacking strong passwords and MFA (Fortinet PSIRT, 2026-06-19; SecurityWeek, 2026-06-22). Reported tradecraft includes a distributed 36-GPU cluster rented from a GenAI company for offline cracking of the harvested hashes, according to researcher Kevin Beaumont (BleepingComputer, 2026-06-22), where Diachenko's earlier claim was a 45-GPU cluster managed through Hashtopolis (BleepingComputer, 2026-06-18); SOCRadar characterises the operators as Russian-speaking (SOCRadar, 2026-06-16).

The delta for defenders is a concrete detection surface that earlier coverage lacked: the tool connects to the FortiGate over SSH and launches the diagnose sniffer packet command (BleepingComputer, 2026-06-22), so hunt for unexpected invocations of that command on the appliance; because harvested Active Directory credentials are the downstream prize, any directory account a FortiBleed-corpus device authenticated against deserves to be treated as exposed, with domain controller logs reviewed for unusual access by those accounts (Fortinet PSIRT, 2026-06-19). Upgrade to firmware with PBKDF2 password hashing to make offline cracking expensive, terminate active sessions, enable MFA and disable external management access.

Updaterun 2026-10-08T0404Z-inteltitleheadlinesummarytagsentitiestechniquesaffected_productsclassificationsourcesevidencesourcing_noteactionsbody

A joint advisory of the FBI and the U.S. Secret Service (JCSA-20261006-01, 2026-10-06) calls FortiBleed an active, global credential-compromise campaign against internet-facing FortiGate firewalls and SSL VPN gateways, cites SOCRadar for more than 86,644 compromised devices in 194 countries, and says attackers are continuing to scan exposed devices with previously obtained credentials (FBI and U.S. Secret Service, 2026-10-06). The operators scan exposed SSL VPN portals, run credential stuffing and password spraying from earlier Fortinet leak dumps and infostealer logs, pull password hashes and session tokens from compromised devices and crack the hashes offline with Hashcat and Hashtopolis on a rented GPU cluster; the advisory ties the success to reused or leaked credentials and a legacy SHA-256 password storage (FBI and U.S. Secret Service, 2026-10-06).

What the advisory adds is the lockout. On a compromised firewall the actors create administrator accounts that were not there before and, in some cases, delete existing accounts or change their passwords, so the owners cannot log in and recovery needs steps beyond patching and password resets (FBI and U.S. Secret Service, 2026-10-06; BleepingComputer, 2026-10-07). Cracked credentials are enriched and validated by scripts that filter out honeypots and rank targets by revenue and network structure; with verified credentials the attackers enumerate Active Directory accounts and spray passwords to find privileged users, and the operation packages working VPN configurations and target lists for sale, the role of an initial-access broker (FBI and U.S. Secret Service, 2026-10-06). The advisory says the chain has been an initial entry point for ransomware affiliates, currently INC/Lynx and Payload (FBI and U.S. Secret Service, 2026-10-06); SOCRadar had linked FortiBleed to INC and Lynx in July after reaching both groups' negotiation panels on a server used in the campaign (BleepingComputer, 2026-10-07).

The advisory's measures: restrict external management through trusted hosts, a local-in policy or no internet administration at all; terminate all administrative and VPN sessions and reset all Fortinet VPN and administrator passwords; require phishing-resistant MFA on remote access and administrator accounts; review users, configuration and REST API keys for entries nobody created, removing unknown keys and refreshing the legitimate ones; enforce PBKDF2 for administrator password storage per Fortinet's guidance for FortiOS 7.2.11 and later; and review firewall, VPN, authentication and domain controller logs for lateral movement (FBI and U.S. Secret Service, 2026-10-06). On the FortiGate itself, in analyst judgement, the administrator accounts, passwords and REST API keys the advisory says to review are recorded in the device's configuration and administrator audit log, which is where an unexpected change shows.

Correctionrun 2026-10-11T1307Z-auditactionsbody

The FBI and Secret Service advisory tells operators to review firewall, VPN, authentication and domain controller logs and to check users, configuration and REST API keys for entries nobody created (FBI and U.S. Secret Service, 2026-10-06); it does not name specific Windows event ids or a domain-wide credential rotation, which earlier hunting guidance here attached to the campaign. The mapping of those checks to the FortiGate's own configuration and administrator audit log is a reading of the advisory, not part of it.

incident18 Jun 05:10Zmulti-sourceOpen finding →

2026-09-10 · view entry permalink →

HIGHCVE-2025-25249exploitedNATOC2

CVE-2025-25249, Fortinet FortiOS/FortiSwitchManager: unauthenticated CAPWAP heap overflow added to CISA KEV, actively exploited since July via the PivotC2 RAT

CISA added CVE-2025-25249 to its Known Exploited Vulnerabilities catalog on 2026-09-09: a heap-based buffer overflow in the cw_acd CAPWAP daemon that FortiOS and FortiSwitchManager use to manage wireless access points, listening unauthenticated on UDP 5246 (CISA, 2026-09-09). SOCRadar's Threat Research Unit reports, with high confidence, that a likely Russian-speaking financially motivated operator has exploited the flaw since at least July 2026, targeting more than 30,000 FortiGate IP addresses and infecting 178 devices (SOCRadar, 2026-09-08). The exploit fingerprints a target's CAPWAP Discovery Response to leak memory pointers and defeat ASLR, matches the reported hardware/software revision against a hardcoded table of thirteen FortiGate and two FortiAP models on FortiOS 7.4.0-7.4.8, then grooms and overflows the daemon's heap-chunk pool via crafted CAPWAP messages to redirect execution (SOCRadar, 2026-09-08). Successful exploitation drops PivotC2, an AI-assisted Node.js RAT purpose-built for FortiGate post-exploitation that maintains a persistent multiplexed TLS channel, supports interactive shells and SOCKS5/HTTP tunneling, and (via an autonomous mode) harvests FortiGate configuration files and encrypted credential stores (VPN PSKs, SSL-VPN and LDAP bind credentials, admin accounts) using a device-specific key pulled from the device's own sync file (SOCRadar, 2026-09-08). In two confirmed US intrusions, operators pivoted further with reverse-SSH relays, network scanning, RDP-enablement registry edits for pass-the-hash, a PowerShell script that downloads and XOR-decrypts a payload before injecting it into svchost.exe via OpenProcess/VirtualAllocEx/WriteProcessMemory, and Exchange mailbox exfiltration to attacker-controlled cloud storage (SOCRadar, 2026-09-08). Affected: FortiOS 6.4 through 7.6.3, FortiSwitchManager 7.0-7.2.6, and FortiSASE 25.1.a.2/25.2.b; fixed in FortiOS 7.6.4/7.4.9/7.2.12/7.0.18 and FortiSwitchManager 7.2.7/7.0.6, with no confirmed fixed FortiSASE build in the sources reached this run.

Triage: an unexplained outbound TLS connection from a FortiGate management interface to a non-Fortinet destination, sustained over hours with periodic small keepalive-sized packets, is the multiplexed C2 channel's signature; normal FortiGate outbound traffic is FortiGuard update/telemetry to Fortinet's own infrastructure, not a persistent operator-controlled tunnel.

The SOCRadar Threat Research Unit (STRU) identified, with high confidence, exploitation of CVE-2025-25249, a heap-based buffer overflow vulnerability in FortiOS and FortiSwitchManager cw_acd daemon.

Active exploitation has been observed since at least July 2026 and is still ongoing.

the actors highly likely leveraged AI to develop the RAT

SOCRadar (STRU) 2026-09-08
vulnerability10 Sep 04:30Zmulti-sourceOpen finding →

Earlier coverage (3)

2026-09-07NOTABLENATOB2Recorded Future's H1 2026 Malware and Vulnerability Trends: two clusters reuse an identical post-exploitation tool stack across thirteen and ten unrelated initial CVEsRecorded Future's Insikt Group published its H1 2026 Malware and Vulnerability Trends report on 2026-09-03, tracking 215 actively exploited CVEs. Its most actionable defender-facing finding is that post-exploitation tool-stack reuse persists across otherwise-unrelated initial-access vulnerabilities: a cluster designated StrikeShark applied an identical six-tool stack across thirteen separate CVEs spanning multiple vendors, and Storm-1175 linked the same credential-theft and ransomware tooling across ten different initial CVEs.2026-08-11HIGHexploitedNATOA1Gunra ransomware-as-a-service: a joint six-agency advisory documents FortiOS edge exploitation, a persistent MFA backdoor built from one fixed OTP value, and a Linux encryptor whose keys can be reconstructedThe FBI, CISA, DC3, NSA, the US Secret Service and South Korea's National Police Agency published joint advisory AA26-222A on 2026-08-10 on Gunra, a Conti-derived double-extortion ransomware-as-a-service that opened an affiliate programme in January 2026 and lists victims across Europe, the Americas, the Middle East, Africa and Asia-Pacific in government services, utilities, healthcare, financial services, transport and critical manufacturing. Initial access is exploitation of the known FortiOS and FortiProxy authentication-bypass flaws CVE-2024-55591 and CVE-2025-24472 on internet-facing firewall and VPN appliances, after which the actors abuse scheduled tasks to create a persistent super-user account, and (in one case) edited the authentication-processing files on a victim's VDI authentication portal so that one attacker-chosen one-time-password value always validated, giving a durable MFA bypass that survives password resets. The advisory also records a defender-usable weakness: the Linux encryptor seeds its key generator with the system clock, so responders may reconstruct keys from file timestamps and recover data without paying.2026-07-28HIGHexploitedNATOA1CVE-2025-68686, FortiOS SSL-VPN: the fix for the symlink-persistence technique is itself bypassable, and CISA now lists it as exploitedCISA added CVE-2025-68686 to the Known Exploited Vulnerabilities catalog on 2026-07-27, confirming in-the-wild abuse of a FortiOS SSL-VPN flaw that lets a remote unauthenticated attacker bypass the patch Fortinet built for the symbolic-link persistence mechanism seen in earlier FortiGate post-exploitation cases. It is not an initial-access vector (Fortinet states an attacker must already have compromised the device at filesystem level through another vulnerability) which is exactly why it matters: any FortiGate that was exposed to an earlier root-filesystem CVE and then "remediated" may still be readable. Fixed in FortiOS 7.6.2 and 7.4.7; 7.2, 7.0 and 6.4 are affected in all versions and require migration to a supported release.

Co-occurring entities

Derived: referenced by the same focused operational entries (weekly summaries and report roundups don't count); ×N counts the shared entries.

Where this entity is cited

  • Threats2
  • Vulns2
  • Deep dive1
  • Research1

Source distribution

  • cisa.gov4 (16%)
  • bleepingcomputer.com3 (12%)
  • fortiguard.fortinet.com3 (12%)
  • fortinet.com2 (8%)
  • securityweek.com2 (8%)
  • socradar.io2 (8%)
  • arcticwolf.com1 (4%)
  • euvdservices.enisa.europa.eu1 (4%)
  • other7 (28%)
All cited sources (25)