Detection rules › Sigma

OpenEDR Spawning Command Shell

Severity
medium
Author
@kostastsale
Source
upstream

Detects the OpenEDR ssh-shellhost.exe spawning a command shell (cmd.exe) or PowerShell with PTY (pseudo-terminal) capabilities. This may indicate remote command execution through OpenEDR's remote management features, which could be legitimate administrative activity or potential abuse of the remote access tool. Threat actors may leverage OpenEDR's remote shell capabilities to execute commands on compromised systems, facilitating lateral movement or other command-and-control operations.

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1059.003 Command and Scripting Interpreter: Windows Command Shell
Lateral MovementT1021.004 Remote Services: SSH
Command & ControlT1219 Remote Access Tools

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.

Stages and Predicates

Stage 1: all of selection_img

CommandLine|contains: --pty
Image|endswith: '\ssh-shellhost.exe'
ParentImage|endswith: '\ITSMService.exe'

Stage 2: all of selection_cli_shell

or:
CommandLine|contains: bash
CommandLine|contains: cmd
CommandLine|contains: powershell
CommandLine|contains: pwsh

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • --pty
  • bash
  • cmd corpus 5 (sigma 5)
  • powershell corpus 16 (sigma 16)
  • pwsh corpus 5 (sigma 5)
Imageends_with
  • \ssh-shellhost.exe
ParentImageends_with
  • \ITSMService.exe