detection.wiki

Detection rules › Sigma

PowerShell Remote Session Creation

Status
test
Severity
medium
Log source
product windows, category ps_script
Author
frack113
Source
github.com/SigmaHQ/sigma

Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system

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: PowerShell Remote Session Creation
id: a0edd39f-a0c6-4c17-8141-261f958e8d8f
status: test
description: |
    Adversaries may abuse PowerShell commands and scripts for execution.
    PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1059.001/T1059.001.md#atomic-test-10---powershell-invoke-downloadcradle
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/new-pssession?view=powershell-7.4
author: frack113
date: 2022-01-06
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|all:
            - 'New-PSSession'
            - '-ComputerName '
    condition: selection
falsepositives:
    - Legitimate administrative script
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ScriptBlockText|contains|all:
        - 'New-PSSession'
        - '-ComputerName '

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
  • -ComputerName corpus 2 (sigma 2)
  • New-PSSession