Detection rules › Sigma

Potential PowerShell Downgrade Attack

Severity
medium
Author
Harish Segar (rule)
Source
upstream

Detects PowerShell downgrade attack by comparing the host versions with the actually used engine version 2.0

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1059.001 Command and Scripting Interpreter: PowerShell

Event coverage

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

Stages and Predicates

Stage 1: selection

or:
CommandLine|contains: ' -v 2 '
CommandLine|contains: ' -ve 2 '
CommandLine|contains: ' -ver 2 '
CommandLine|contains: ' -vers 2 '
CommandLine|contains: ' -versi 2 '
CommandLine|contains: ' -versio 2 '
CommandLine|contains: ' -version 2 '
Image|endswith: '\powershell.exe'

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
  • -v 2
  • -ve 2
  • -ver 2
  • -vers 2
  • -versi 2
  • -versio 2
  • -version 2
Imageends_with
  • \powershell.exe corpus 143 (sigma 143)