LSASS Access From Potentially White-Listed Processes — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-02-10 / 2023-11-29.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: ab1223450ca88a27718a850192cdfc4ee9740c39a1d4aab105aa6b81f71d7a77

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: LSASS Access From Potentially White-Listed Processes
id: 4be8b654-0c01-4c9d-a10c-6b28467fc651
status: test
description: |
    Detects a possible process memory dump that uses a white-listed filename like TrolleyExpress.exe as a way to dump the LSASS process memory without Microsoft Defender interference
references:
    - https://twitter.com/_xpn_/status/1491557187168178176
    - https://www.ired.team/offensive-security/credential-access-and-credential-dumping/dump-credentials-from-lsass-process-without-mimikatz
    - https://twitter.com/mrd0x/status/1460597833917251595
author: Florian Roth (Nextron Systems)
date: 2022-02-10
modified: 2023-11-29
tags:
    - attack.credential-access
    - attack.t1003.001
    - attack.s0002
logsource:
    category: process_access
    product: windows
detection:
    selection:
        TargetImage|endswith: '\lsass.exe'
        SourceImage|endswith:
            - '\TrolleyExpress.exe'  # Citrix
            - '\ProcessDump.exe'     # Cisco Jabber
            - '\dump64.exe'          # Visual Studio
        GrantedAccess|endswith:
            - '10'
            - '30'
            - '50'
            - '70'
            - '90'
            - 'B0'
            - 'D0'
            - 'F0'
            - '18'
            - '38'
            - '58'
            - '78'
            - '98'
            - 'B8'
            - 'D8'
            - 'F8'
            - '1A'
            - '3A'
            - '5A'
            - '7A'
            - '9A'
            - 'BA'
            - 'DA'
            - 'FA'
            - '0x14C2'  # https://github.com/b4rtik/ATPMiniDump/blob/76304f93b390af3bb66e4f451ca16562a479bdc9/ATPMiniDump/ATPMiniDump.c
            - 'FF'
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://twitter.com/_xpn_/status/1491557187168178176
• https://www.ired.team/offensive-security/credential-access-and-credential-dumping/dump-credentials-from-lsass-process-without-mimikatz
• https://twitter.com/mrd0x/status/1460597833917251595