Win Susp Computer Name Containing Samtheadmin — Sigma Rule

Rule metadata and linked tags

Author: elhoim. Source status: test; severity: critical. Source dates: 2022-09-09 / 2023-01-04.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 7008dd1bacdcba1088567f2d521a6f18dddd10d9e6f5021550ebbfe54509966f

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: Win Susp Computer Name Containing Samtheadmin
id: 39698b3f-da92-4bc6-bfb5-645a98386e45
status: test
description: Detects suspicious computer name samtheadmin-{1..100}$ generated by hacktool
references:
    - https://twitter.com/malmoeb/status/1511760068743766026
    - https://github.com/helloexp/0day/blob/614227a7b9beb0e91e7e2c6a5e532e6f7a8e883c/00-CVE_EXP/CVE-2021-42287/sam-the-admin/sam_the_admin.py
author: elhoim
date: 2022-09-09
modified: 2023-01-04
tags:
    - attack.initial-access
    - cve.2021-42278
    - cve.2021-42287
    - attack.persistence
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1078
logsource:
    service: security
    product: windows
detection:
    # Not adding an EventID on purpose to try to match on any event in security (including use of account), not just 4741 (computer account created)
    selection1:
        SamAccountName|startswith: 'SAMTHEADMIN-'
        SamAccountName|endswith: '$'
    selection2:
        TargetUserName|startswith: 'SAMTHEADMIN-'
        TargetUserName|endswith: '$'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: critical

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://twitter.com/malmoeb/status/1511760068743766026
• https://github.com/helloexp/0day/blob/614227a7b9beb0e91e7e2c6a5e532e6f7a8e883c/00-CVE_EXP/CVE-2021-42287/sam-the-admin/sam_the_admin.py