SAWFLY
malware · malware:sawfly
Lightweight PHP web shell that Google's Threat Intelligence Group found on BeyondTrust Remote Support appliances compromised through CVE-2026-102764; it evaluates attacker-supplied code sent in a POST parameter and runs as the appliance's unprivileged site account (GTIG, 2026-10-15).
Action items (3)
Do-now tasks recorded on the entries about SAWFLY, newest first. Check the date before acting on an older one.
- Immediate action: BeyondTrust and Google's Threat Intelligence Group confirm that an unauthenticated flaw in Remote Support (all versions up to 26.2.3) was exploited as a zero-day from late August 2026, GTIG attributing it to a suspected China-nexus espionage actor, and GTIG warns organizations to prepare for widespread exploitation now that the flaw is public. Apply the BT26-05-RS patch to every self-hosted appliance (builds older than 24.3.1 must be upgraded first). The actor's persistence survives reboot and configuration reset and it deletes on-appliance logs, so snapshot and collect off-box logs from any appliance that was internet-reachable on an affected build, then redeploy from a clean patched image any whose compromise status is confirmed or unknown and rotate everything it held.2026-10-16CVE-2026-102764
- Apply the BT26-05-RS patch to every self-hosted BeyondTrust Remote Support appliance now and confirm in the /appliance interface that it is installed (a build older than 24.3.1 must be upgraded first, which closes the hole but does not undo earlier exposure); apply it to self-hosted Privileged Remote Access appliances too, which BeyondTrust patched as a precaution.2026-10-16CVE-2026-102764
- For every appliance that was internet-reachable on a build up to 26.2.3 at any time since late August 2026: before any change, snapshot a virtual appliance with memory and export its disk, and collect the off-box syslog, reverse-proxy or WAF and perimeter firewall logs because the actor deletes on-appliance logs; then redeploy from a clean, fully patched image every appliance whose compromise status is confirmed or unknown, and rotate the credentials it held in dependency order, including the Remote Support Vault and any credential typed into a support session.2026-10-16CVE-2026-102764
Defender insights
What each entry about SAWFLY tells a defender to do, newest first.
Relationships explore in graph
Typed, source-stated connections from the entity registry; each edge cites the entry whose reporting establishes it.
used by
- VerdantBambooGTIG attributes the SAWFLY web shell found after CVE-2026-102764 exploitation to ARMORY CASTLE
Story timeline
Hunting pivots
ATT&CK techniques (14 across 8 tactics)
14 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 · Exploit Public-Facing Application
- PersistenceBoot or Logon Initialization Scripts · Valid Accounts · Account Manipulation · Server Software Component: Web Shell
- Privilege EscalationBoot or Logon Initialization Scripts · Valid Accounts · Account Manipulation · Abuse Elevation Control Mechanism: Setuid and Setgid · Abuse Elevation Control Mechanism: Sudo and Sudo Caching
- StealthIndicator Removal: File Deletion · Valid Accounts
- Defense ImpairmentDisable or Modify Tools: Clear Linux or Mac System Logs
- Credential AccessCredentials from Password Stores
- CollectionData from Local System
- Command and ControlProxy · Remote Access Tools · Protocol Tunneling
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/cve-2026-102764-beyondtrust-remote-support-zero-day · 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/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Persistence TA0003
T1037Boot or Logon Initialization Scripts×1
Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence. Initialization scripts can be used to perform administrative functions, which may often execute other programs or send information to an internal logging server. These scripts can vary based on operating system and whether applied locally or remotely.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · 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/cve-2026-102764-beyondtrust-remote-support-zero-day · 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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · 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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Privilege Escalation TA0004
T1037Boot or Logon Initialization Scripts×1
Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence. Initialization scripts can be used to perform administrative functions, which may often execute other programs or send information to an internal logging server. These scripts can vary based on operating system and whether applied locally or remotely.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · 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/cve-2026-102764-beyondtrust-remote-support-zero-day · 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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
T1548.001Abuse Elevation Control Mechanism: Setuid and Setgid×1
An adversary may abuse configurations where an application has the setuid or setgid bits set in order to get code running in a different (and possibly more privileged) user’s context. On Linux or macOS, when the setuid or setgid bits are set for an application binary, the application will run with the privileges of the owning user or group respectively. Normally an application is run in the current user’s context, regardless of which user or group owns the application. However, there are instances where programs need to be executed in an elevated context to function properly, but the user running them may not have the specific required privileges.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
T1548.003Abuse Elevation Control Mechanism: Sudo and Sudo Caching×1
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges. Adversaries may do this to execute commands as other users or spawn processes with higher privileges.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Stealth TA0005
T1070.004Indicator Removal: File Deletion×1
Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary (ex: Ingress Tool Transfer) may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · 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/cve-2026-102764-beyondtrust-remote-support-zero-day · 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/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Credential Access TA0006
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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Collection TA0009
T1005Data from Local System×1
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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Command and Control TA0011
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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
T1219Remote Access Tools×1
An adversary may use legitimate remote access tools to establish an interactive command and control channel within a network. Remote access tools create a session between two trusted hosts through a graphical interface, a command line interaction, a protocol tunnel via development or management software, or hardware-level access such as KVM (Keyboard, Video, Mouse) over IP solutions. Desktop support software (usually graphical interface) and remote management software (typically command line interface) allow a user to control a computer remotely as if they are a local user inheriting the user or software permissions. This software is commonly used for troubleshooting, software installation, and system management. Adversaries may similarly abuse response features included in EDR and other defensive tools that enable remote access.
Evidence: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · 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: 2026-10-16/cve-2026-102764-beyondtrust-remote-support-zero-day · ATT&CK page ↗
Entries about SAWFLY (1)
Co-occurring entities
Derived: referenced by the same focused operational entries (weekly summaries and report roundups don't count); ×N counts the shared entries.
- BARECLAW×1
- BeyondTrust Remote Support×1
- BeyondTrust Remote Support: improper origin validation in an internal messaging component lets an unauthenticated attacker perform file operations, exploited as a zero-day since late August 2026 (BT26-05)×1
- VerdantBamboo×1
Where this entity is cited
Source distribution
- beyondtrust.com2 (67%)
- cloud.google.com1 (33%)
All cited sources (3)
- beyondtrust.comBeyondTrust (blog)https://www.beyondtrust.com/blog/entry/bt26-05
- beyondtrust.comBeyondTrust (advisory BT26-05)https://www.beyondtrust.com/trust-center/security-advisories/bt26-05
- cloud.google.comGoogle Threat Intelligence Group / Mandianthttps://cloud.google.com/blog/topics/threat-intelligence/armory-castle-exploits-beyondtrust/