Detection rules › Sigma

DCOM InternetExplorer.Application Iertutil DLL Hijack - Security

Severity
high
Author
Roberto Rodriguez @Cyb3rWard0g, Open Threat Research (OTR)
Source
upstream

Detects a threat actor creating a file named iertutil.dll in the C:\Program Files\Internet Explorer\ directory over the network for a DCOM InternetExplorer DLL Hijack scenario.

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021.002 Remote Services: SMB/Windows Admin Shares, T1021.003 Remote Services: Distributed Component Object Model

Event coverage

ProviderEvent IDTitle
Security-Auditing5145A network share object was checked to see whether client can be granted desired access.

Stages and Predicates

Stage 1: selection

RelativeTargetName|endswith: '\Internet Explorer\iertutil.dll'

Stage 2: not filter

SubjectUserName|endswith: '$'

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
RelativeTargetNameends_with
  • \Internet Explorer\iertutil.dll
SubjectUserNameends_with
  • $ corpus 18 (sigma 14, elastic 4)

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.