Detection rules › Sigma

Hidden Powershell in Link File Pattern

Severity
medium
Author
frack113
Source
upstream

Detects events that appear when a user click on a link file with a powershell command in it

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

CommandLine|contains: .lnk
CommandLine|contains: powershell
Image: 'C:\Windows\System32\cmd.exe'
ParentImage: 'C:\Windows\explorer.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
  • .lnk corpus 2 (sigma 2)
  • powershell corpus 16 (sigma 16)
Imageeq
  • C:\Windows\System32\cmd.exe corpus 3 (sigma 3)
ParentImageeq
  • C:\Windows\explorer.exe corpus 2 (sigma 2)