Detection rules › Sigma

Uncommon Network Connection Initiated By Certutil.EXE

Severity
high
Author
frack113, Florian Roth (Nextron Systems)
Source
upstream

Detects a network connection initiated by the certutil.exe utility. Attackers can abuse the utility in order to download malware or additional payloads.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1105 Ingress Tool Transfer

Event coverage

ProviderEvent IDTitle
Sysmon3Network connection

Stages and Predicates

Stage 1: selection

DestinationPort: [135, 443, 445, 80]
Image|endswith: '\certutil.exe'
Initiated: true

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
DestinationPorteq
  • 135
  • 443 corpus 7 (sigma 7)
  • 445 corpus 3 (sigma 3)
  • 80 corpus 6 (sigma 6)
Imageends_with
  • \certutil.exe corpus 34 (sigma 34)
Initiatedeq
  • true corpus 40 (sigma 40)