HackTool - Empire PowerShell Launch Parameters

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

Detects suspicious powershell command line parameters used in Empire

Known false positives

Other tools that incidentally use the same command line parameters

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.001` Command and Scripting Interpreter: PowerShell

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: HackTool - Empire PowerShell Launch Parameters
id: 79f4ede3-402e-41c8-bc3e-ebbf5f162581
status: test
description: Detects suspicious powershell command line parameters used in Empire
references:
    - https://github.com/EmpireProject/Empire/blob/c2ba61ca8d2031dad0cfc1d5770ba723e8b710db/lib/common/helpers.py#L165
    - https://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/lib/modules/powershell/persistence/powerbreach/deaduser.py#L191
    - https://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/lib/modules/powershell/persistence/powerbreach/resolver.py#L178
    - https://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/data/module_source/privesc/Invoke-EventVwrBypass.ps1#L64
author: Florian Roth (Nextron Systems)
date: 2019-04-20
modified: 2023-02-21
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains:
            - ' -NoP -sta -NonI -W Hidden -Enc '
            - ' -noP -sta -w 1 -enc '
            - ' -NoP -NonI -W Hidden -enc '
            - ' -noP -sta -w 1 -enc'
            - ' -enc  SQB'
            - ' -nop -exec bypass -EncodedCommand '
    condition: selection
falsepositives:
    - Other tools that incidentally use the same command line parameters
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    CommandLine|contains:
        - ' -NoP -sta -NonI -W Hidden -Enc '
        - ' -noP -sta -w 1 -enc '
        - ' -NoP -NonI -W Hidden -enc '
        - ' -noP -sta -w 1 -enc'
        - ' -enc  SQB'
        - ' -nop -exec bypass -EncodedCommand '

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`-NoP -NonI -W Hidden -enc` `-NoP -sta -NonI -W Hidden -Enc` `-enc SQB` `-noP -sta -w 1 -enc` `-noP -sta -w 1 -enc` `-nop -exec bypass -EncodedCommand`	`field:"CommandLine" kind:match`

HackTool - Empire PowerShell Launch Parameters

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`