Detection rules › Kusto Query Language

Base64 encoded Windows process command-lines (Normalized Process Events)

Author
Yuval Naor
Source
upstream

'Identifies instances of a base64 encoded PE file header seen in the process command line parameter. To use this analytics rule, make sure you have deployed the ASIM normalization parsers'

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1059 Command and Scripting Interpreter
Defense EvasionT1027 Obfuscated Files or Information, T1140 Deobfuscate/Decode Files or Information

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon5Process terminated
Security-Auditing4688A new process has been created.
Security-Auditing4689A process has exited.

Stages and Predicates

Stage 1: source

imProcessCreate

Stage 2: where

CommandLine contains "TVqQAAMAAAAEAAA"

Stage 3: where

Process is_not_null

Stage 4: summarize

Stage 5: extend

Stage 6: extend

Stage 7: extend

Stage 8: project-away

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
CommandLinecontains
  • TVqQAAMAAAAEAAA