Detection rules › Sigma

Suspicious GrpConv Execution

Status
test
Severity
high
Log source
category process_creation, product windows
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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

Telemetry coverage

Rule body

title: Suspicious GrpConv Execution
id: f14e169e-9978-4c69-acb3-1cff8200bc36
status: test
description: Detects the suspicious execution of a utility to convert Windows 3.x .grp files or for persistence purposes by malicious software or actors
references:
    - https://twitter.com/0gtweet/status/1526833181831200770
author: Florian Roth (Nextron Systems)
date: 2022-05-19
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - 'grpconv.exe -o'
            - 'grpconv -o'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

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

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • grpconv -o
  • grpconv.exe -o
field:"CommandLine" kind:match