Detection rules › Sigma

Suspicious GrpConv Execution

Severity
high
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects the suspicious execution of a utility to convert Windows 3.x .grp files or for persistence purposes by malicious software or actors

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1547 Boot or Logon Autostart Execution
Privilege EscalationT1547 Boot or Logon Autostart Execution

Event coverage

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

Stages and Predicates

Stage 1: selection

or:
CommandLine|contains: 'grpconv -o'
CommandLine|contains: 'grpconv.exe -o'

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
  • grpconv -o
  • grpconv.exe -o