Detection rules › Sigma

Suspicious Rundll32 Invoking Inline VBScript

Severity
high
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects suspicious process related to rundll32 based on command line that invokes inline VBScript as seen being used by UNC2452

MITRE ATT&CK coverage

TacticTechniques
Privilege EscalationT1055 Process Injection
Defense EvasionT1055 Process Injection

Event coverage

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

Stages and Predicates

Stage 1: selection

CommandLine|contains: Execute
CommandLine|contains: RegRead
CommandLine|contains: rundll32.exe
CommandLine|contains: window.close

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
  • Execute
  • RegRead
  • rundll32.exe corpus 4 (sigma 4)
  • window.close

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.