PowerShell Profile Modification

Status: test
Severity: medium
Log source: category file_event, product windows
Author: HieuTT35, Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects the creation or modification of a powershell profile which could indicate suspicious activity as the profile can be used as a mean of persistence

Known false positives

System administrator creating Powershell profile manually

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546.013` Event Triggered Execution: PowerShell Profile
Privilege Escalation	`T1546.013` Event Triggered Execution: PowerShell Profile

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 11: FileCreate

Rule body

title: PowerShell Profile Modification
id: b5b78988-486d-4a80-b991-930eff3ff8bf
status: test
description: Detects the creation or modification of a powershell profile which could indicate suspicious activity as the profile can be used as a mean of persistence
references:
    - https://www.welivesecurity.com/2019/05/29/turla-powershell-usage/
    - https://persistence-info.github.io/Data/powershellprofile.html
author: HieuTT35, Nasreddine Bencherchali (Nextron Systems)
date: 2019-10-24
modified: 2023-10-23
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1546.013
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|endswith:
            - '\Microsoft.PowerShell_profile.ps1'
            - '\PowerShell\profile.ps1'
            - '\Program Files\PowerShell\7-preview\profile.ps1'
            - '\Program Files\PowerShell\7\profile.ps1'
            - '\Windows\System32\WindowsPowerShell\v1.0\profile.ps1'
            - '\WindowsPowerShell\profile.ps1'
    condition: selection
falsepositives:
    - System administrator creating Powershell profile manually
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    TargetFilename|endswith:
        - '\Microsoft.PowerShell_profile.ps1'
        - '\PowerShell\profile.ps1'
        - '\Program Files\PowerShell\7-preview\profile.ps1'
        - '\Program Files\PowerShell\7\profile.ps1'
        - '\Windows\System32\WindowsPowerShell\v1.0\profile.ps1'
        - '\WindowsPowerShell\profile.ps1'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetFilename`	ends_with	`\Microsoft.PowerShell_profile.ps1` `\PowerShell\profile.ps1` `\Program Files\PowerShell\7-preview\profile.ps1` `\Program Files\PowerShell\7\profile.ps1` `\WindowsPowerShell\profile.ps1` `\Windows\System32\WindowsPowerShell\v1.0\profile.ps1`	`field:"TargetFilename" kind:ends_with`