SMB Spoolss Name Piped Usage — Sigma Rule

Rule metadata and linked tags

Author: OTR (Open Threat Research), @neu5ron. Source status: test; severity: medium. Source dates: 2018-11-28 / 2022-10-09.

{
  "product": "zeek",
  "service": "smb_files"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 2228d3e118fcb8d634052c8e99db1ff3a136aa9c17d48c76e3b78d2200e40ee3

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: SMB Spoolss Name Piped Usage
id: bae2865c-5565-470d-b505-9496c87d0c30
status: test
description: Detects the use of the spoolss named pipe over SMB. This can be used to trigger the authentication via NTLM of any machine that has the spoolservice enabled.
references:
    - https://posts.specterops.io/hunting-in-active-directory-unconstrained-delegation-forests-trusts-71f2b33688e1
    - https://dirkjanm.io/a-different-way-of-abusing-zerologon/
    - https://twitter.com/_dirkjan/status/1309214379003588608
author: OTR (Open Threat Research), @neu5ron
date: 2018-11-28
modified: 2022-10-09
tags:
    - attack.lateral-movement
    - attack.t1021.002
logsource:
    product: zeek
    service: smb_files
detection:
    selection:
        path|endswith: 'IPC$'
        name: spoolss
    condition: selection
falsepositives:
    - Domain Controllers that are sometimes, commonly although should not be, acting as printer servers too
level: medium

Original YAML and metadata in JSON

False positives

• Domain Controllers that are sometimes, commonly although should not be, acting as printer servers too

Source references

• https://posts.specterops.io/hunting-in-active-directory-unconstrained-delegation-forests-trusts-71f2b33688e1
• https://dirkjanm.io/a-different-way-of-abusing-zerologon/
• https://twitter.com/_dirkjan/status/1309214379003588608