PowerShell Script With File Hostname Resolving Capabilities — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-05-05 / not supplied.

{
  "product": "windows",
  "category": "ps_script",
  "definition": "bade5735-5ab0-4aa7-a642-a11be0e40872"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d404b8038d1eba5e89f39ab48708a118ed0e188b7f9c76862eb214d4476fcaad

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: PowerShell Script With File Hostname Resolving Capabilities
id: fbc5e92f-3044-4e73-a5c6-1c4359b539de
status: test
description: Detects PowerShell scripts that have capabilities to read files, loop through them and resolve DNS host entries.
references:
    - https://www.fortypoundhead.com/showcontent.asp?artid=24022
    - https://labs.withsecure.com/publications/fin7-target-veeam-servers
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-05
tags:
    - attack.exfiltration
    - attack.t1020
logsource:
    product: windows
    category: ps_script
    definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'Get-content '
            - 'foreach'
            - '[System.Net.Dns]::GetHostEntry'
            - 'Out-File'
    condition: selection
falsepositives:
    - The same functionality can be implemented by admin scripts, correlate with name and creator
level: medium

Original YAML and metadata in JSON

False positives

• The same functionality can be implemented by admin scripts, correlate with name and creator

Source references

• https://www.fortypoundhead.com/showcontent.asp?artid=24022
• https://labs.withsecure.com/publications/fin7-target-veeam-servers