Detection rules › Sigma

Base64 MZ Header In CommandLine

Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects encoded base64 MZ header in the commandline

Event coverage

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

Stages and Predicates

Stage 1: selection

or:
CommandLine|contains: TVoAAAAAAAAAAAAA
CommandLine|contains: TVpQAAIAAAAEAA8A
CommandLine|contains: TVpTAQEAAAAEAAAA
CommandLine|contains: TVqAAAEAAAAEABAA
CommandLine|contains: TVqQAAMAAAAEAAAA

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
  • TVoAAAAAAAAAAAAA
  • TVpQAAIAAAAEAA8A
  • TVpTAQEAAAAEAAAA
  • TVqAAAEAAAAEABAA
  • TVqQAAMAAAAEAAAA