Detection rules › Sigma

Potential Renamed Rundll32 Execution

Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects when 'DllRegisterServer' is called in the commandline and the image is not rundll32. This could mean that the 'rundll32' utility has been renamed in order to avoid detection

Event coverage

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

Stages and Predicates

Stage 1: selection

CommandLine|contains: DllRegisterServer

Stage 2: not filter

Image|endswith: '\rundll32.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
  • DllRegisterServer
Imageends_with
  • \rundll32.exe corpus 76 (sigma 76)