DCERPC SMB Spoolss Named Pipe — Sigma Rule

Rule metadata and linked tags

Author: OTR (Open Threat Research). Source status: test; severity: medium. Source dates: 2018-11-28 / 2022-08-11.

{
  "product": "windows",
  "service": "security"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 03b86f4282d6432a63de5ab772a8bb37547c964a1b1cfe67d5b5af046d08dd40

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: DCERPC SMB Spoolss Named Pipe
id: 214e8f95-100a-4e04-bb31-ef6cba8ce07e
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)
date: 2018-11-28
modified: 2022-08-11
tags:
    - attack.lateral-movement
    - attack.t1021.002
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 5145
        ShareName: '\\\\\*\\IPC$' # looking for the string \\*\IPC$
        RelativeTargetName: spoolss
    condition: selection
falsepositives:
    - 'Domain Controllers acting as printer servers too? :)'
level: medium

Original YAML and metadata in JSON

False positives

• Domain Controllers 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