LoFP / runas usage spawning one of the listed binaries under a different account

Techniques

• t1055
• t1134

Sample rules

Suspicious Cross-User Process Spawn

• source: sigma
• technicques:
  • t1055
  • t1134

Description

Detects suspicious spawning of a process under a different user context than the parent process. Processes such as notepad.exe, calculator etc. are generally spawned under the same user context and also they are often targeted as sacrificial process or decoy process to check successful privilege escalation.

Detection logic

condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
filter_main_same_user:
  User|fieldref: ParentUser
filter_optional_empty_user:
- ParentUser:
  - ''
  - '-'
- User:
  - ''
  - '-'
filter_optional_parent_null:
  ParentUser: null
filter_optional_user_null:
  User: null
selection:
  Image|endswith:
  - \notepad.exe
  - \calc.exe
  - \mspaint.exe
  - \wordpad.exe
  - \write.exe