Potential Recon Activity Via Nltest.EXE — Sigma Rule

Rule metadata and linked tags

Author: Craig Young, oscd.community, Georg Lauenstein. Source status: test; severity: medium. Source dates: 2021-07-24 / 2023-12-15.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: a40330e4f631169523a802f3c943110077553471a6a717d3e2c3263adcd43059

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: Potential Recon Activity Via Nltest.EXE
id: 5cc90652-4cbd-4241-aa3b-4b462fa5a248
related:
    - id: 410ad193-a728-4107-bc79-4419789fcbf8
      type: similar
    - id: 903076ff-f442-475a-b667-4f246bcc203b
      type: similar
    - id: 77815820-246c-47b8-9741-e0def3f57308
      type: obsolete
status: test
description: Detects nltest commands that can be used for information discovery
references:
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731935(v=ws.11)
    - https://thedfirreport.com/2021/08/16/trickbot-leads-up-to-fake-1password-installation/
    - https://thedfirreport.com/2020/10/18/ryuk-in-5-hours/
    - https://book.hacktricks.xyz/windows/basic-cmd-for-pentesters
    - https://research.nccgroup.com/2022/08/19/back-in-black-unlocking-a-lockbit-3-0-ransomware-attack/
    - https://eqllib.readthedocs.io/en/latest/analytics/03e231a6-74bc-467a-acb1-e5676b0fb55e.html
    - https://redcanary.com/blog/how-one-hospital-thwarted-a-ryuk-ransomware-outbreak/
    - https://github.com/redcanaryco/atomic-red-team/blob/5360c9d9ffa3b25f6495f7a16e267b719eba2c37/atomics/T1482/T1482.md#atomic-test-2---windows---discover-domain-trusts-with-nltest
author: Craig Young, oscd.community, Georg Lauenstein
date: 2021-07-24
modified: 2023-12-15
tags:
    - attack.discovery
    - attack.t1016
    - attack.t1482
logsource:
    category: process_creation
    product: windows
detection:
    selection_nltest:
        - Image|endswith: '\nltest.exe'
        - OriginalFileName: 'nltestrk.exe'
    selection_recon:
        - CommandLine|contains|all:
              - 'server'
              - 'query'
        - CommandLine|contains:
              - '/user'
              - 'all_trusts' # Flag for /domain_trusts
              - 'dclist:'
              - 'dnsgetdc:'
              - 'domain_trusts'
              - 'dsgetdc:'
              - 'parentdomain'
              - 'trusted_domains'
    condition: all of selection_*
falsepositives:
    - Legitimate administration use but user and host must be investigated
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate administration use but user and host must be investigated

Source references

• https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731935(v=ws.11)
• https://thedfirreport.com/2021/08/16/trickbot-leads-up-to-fake-1password-installation/
• https://thedfirreport.com/2020/10/18/ryuk-in-5-hours/
• https://book.hacktricks.xyz/windows/basic-cmd-for-pentesters
• https://research.nccgroup.com/2022/08/19/back-in-black-unlocking-a-lockbit-3-0-ransomware-attack/
• https://eqllib.readthedocs.io/en/latest/analytics/03e231a6-74bc-467a-acb1-e5676b0fb55e.html
• https://redcanary.com/blog/how-one-hospital-thwarted-a-ryuk-ransomware-outbreak/
• https://github.com/redcanaryco/atomic-red-team/blob/5360c9d9ffa3b25f6495f7a16e267b719eba2c37/atomics/T1482/T1482.md#atomic-test-2---windows---discover-domain-trusts-with-nltest