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CL-STA-0954

actor · actor:cl-sta-0954 single-source

Unit 42 designation, also UNC5820, for the cluster that exploited FortiManager CVE-2024-47575 against a telecommunications organization in September 2024 and later installed PEERSTITCH on its FortiGate firewalls through CVE-2025-61624 (Unit 42, 2026-10-14).

Aliases: UNC5820

Coverage
1
first 2026-10-16 → 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
notable
1 notable
Targets
telco
sectors: telco
Sources cited
3
2 hosts

Defender insights

What each entry about CL-STA-0954 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

Relationships explore in graph

Typed, source-stated connections from the entity registry; each edge cites the entry whose reporting establishes it.

uses

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
ATT&CK techniques (10 across 8 tactics)

10 techniques observed across 1 entry about this entity, derived from entry metadata and body evidence, never asserted without a published entry behind it · pinned to MITRE ATT&CK v19.2 · compare on the matrix · Navigator layer (JSON)

  • Initial AccessValid Accounts · External Remote Services · Exploit Public-Facing Application
  • ExecutionCommand and Scripting Interpreter: JavaScript
  • PersistenceValid Accounts · External Remote Services
  • Privilege EscalationProcess Injection: Ptrace System Calls · Exploitation for Privilege Escalation · Valid Accounts
  • StealthProcess Injection: Ptrace System Calls · Indicator Removal · Valid Accounts
  • Defense ImpairmentDisable or Modify Tools: Clear Linux or Mac System Logs
  • Credential AccessNetwork Sniffing · Unsecured Credentials: Credentials In Files
  • DiscoveryNetwork Sniffing

Initial Access TA0001

T1078Valid Accounts×1

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 · ATT&CK page ↗

T1133External Remote Services×1

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 · ATT&CK page ↗

T1190Exploit Public-Facing Application×1

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 · ATT&CK page ↗

Execution TA0002

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 ↗

Persistence TA0003

T1078Valid Accounts×1

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 · ATT&CK page ↗

T1133External Remote Services×1

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 · ATT&CK page ↗

Privilege Escalation TA0004

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×1

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 · ATT&CK page ↗

Stealth TA0005

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 ↗

T1078Valid Accounts×1

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 · ATT&CK page ↗

Defense Impairment TA0112

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

T1040Network Sniffing×1

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 · ATT&CK page ↗

T1552.001Unsecured Credentials: Credentials In Files×1

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 · ATT&CK page ↗

Discovery TA0007

T1040Network Sniffing×1

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 · ATT&CK page ↗

Entries about CL-STA-0954 (1)

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 →

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

  • Threats1

Source distribution

  • fortiguard.fortinet.com2 (67%)
  • unit42.paloaltonetworks.com1 (33%)