Detection rules › Sigma

Mimikatz DC Sync

Status
test
Severity
high
Log source
product windows, service security
Author
Benjamin Delpy, Florian Roth (Nextron Systems), Scott Dermott, Sorina Ionescu
Source
github.com/SigmaHQ/sigma

Detects Mimikatz DC sync security events

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003.006 OS Credential Dumping: DCSync

Event coverage

Rule body yaml

title: Mimikatz DC Sync
id: 611eab06-a145-4dfa-a295-3ccc5c20f59a
status: test
description: Detects Mimikatz DC sync security events
references:
    - https://twitter.com/gentilkiwi/status/1003236624925413376
    - https://gist.github.com/gentilkiwi/dcc132457408cf11ad2061340dcb53c2
    - https://blog.blacklanternsecurity.com/p/detecting-dcsync?s=r
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4662
author: Benjamin Delpy, Florian Roth (Nextron Systems), Scott Dermott, Sorina Ionescu
date: 2018-06-03
modified: 2022-04-26
tags:
    - attack.credential-access
    - attack.s0002
    - attack.t1003.006
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 4662
        Properties|contains:
            - 'Replicating Directory Changes All'
            - '1131f6ad-9c07-11d1-f79f-00c04fc2dcd2'
            - '1131f6aa-9c07-11d1-f79f-00c04fc2dcd2'
            - '9923a32a-3607-11d2-b9be-0000f87a36b2'
            - '89e95b76-444d-4c62-991a-0facbeda640c'
        AccessMask: '0x100'
    filter1:
        SubjectDomainName: 'Window Manager'
    filter2:
        SubjectUserName|startswith:
            - 'NT AUT'
            - 'MSOL_'
    filter3:
        SubjectUserName|endswith: '$'
    condition: selection and not 1 of filter*
falsepositives:
    - Valid DC Sync that is not covered by the filters; please report
    - Local Domain Admin account used for Azure AD Connect
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter*

Stage 1: selection

selection:
    EventID: 4662
    Properties|contains:
        - 'Replicating Directory Changes All'
        - '1131f6ad-9c07-11d1-f79f-00c04fc2dcd2'
        - '1131f6aa-9c07-11d1-f79f-00c04fc2dcd2'
        - '9923a32a-3607-11d2-b9be-0000f87a36b2'
        - '89e95b76-444d-4c62-991a-0facbeda640c'
    AccessMask: '0x100'

Stage 2: not filter*

filter1:
    SubjectDomainName: 'Window Manager'
filter2:
    SubjectUserName|startswith:
        - 'NT AUT'
        - 'MSOL_'
filter3:
    SubjectUserName|endswith: '$'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
SubjectDomainNameeqWindow Manager
SubjectUserNameends_with$
SubjectUserNamestarts_withMSOL_
SubjectUserNamestarts_withNT AUT

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
AccessMaskeq
  • 0x100 corpus 5 (sigma 2, splunk 2, elastic 1)
Propertiesmatch
  • 1131f6aa-9c07-11d1-f79f-00c04fc2dcd2 corpus 6 (sigma 3, elastic 2, kusto 1)
  • 1131f6ad-9c07-11d1-f79f-00c04fc2dcd2 corpus 6 (sigma 3, elastic 2, kusto 1)
  • 89e95b76-444d-4c62-991a-0facbeda640c corpus 6 (sigma 3, elastic 2, kusto 1)
  • 9923a32a-3607-11d2-b9be-0000f87a36b2 corpus 2 (sigma 2)
  • Replicating Directory Changes All