detection.wiki

Detection rules › Sigma

Malicious ShellIntel PowerShell Commandlets

Status
test
Severity
high
Log source
product windows, category ps_script
Author
Max Altgelt (Nextron Systems), Tobias Michalski (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects Commandlet names from ShellIntel exploitation scripts.

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1059.001 Command and Scripting Interpreter: PowerShell

Event coverage

ProviderEventTitle
PowerShellEvent ID 4104Creating Scriptblock text (MessageNumber of MessageTotal).

Rule body yaml

title: Malicious ShellIntel PowerShell Commandlets
id: 402e1e1d-ad59-47b6-bf80-1ee44985b3a7
status: test
description: Detects Commandlet names from ShellIntel exploitation scripts.
references:
    - https://github.com/Shellntel/scripts/
author: Max Altgelt (Nextron Systems), Tobias Michalski (Nextron Systems)
date: 2021-08-09
modified: 2023-01-02
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains:
            - 'Invoke-SMBAutoBrute'
            - 'Invoke-GPOLinks'
            # - 'Out-Minidump' # Covered in 89819aa4-bbd6-46bc-88ec-c7f7fe30efa6
            - 'Invoke-Potato'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ScriptBlockText|contains:
        - 'Invoke-SMBAutoBrute'
        - 'Invoke-GPOLinks'
        - 'Invoke-Potato'

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
ScriptBlockTextmatch
  • Invoke-GPOLinks
  • Invoke-Potato
  • Invoke-SMBAutoBrute