Sigma rule: PetitPotam Suspicious Kerberos TGT Request

Rule

Title

PetitPotam Suspicious Kerberos TGT Request

Status

test

Level

high

Author

Mauricio Velazco, Michael Haag

Date

2021-09-02

Modified

2022-10-05

File

rules/windows/builtin/security/win_security_petitpotam_susp_tgt_request.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detect suspicious Kerberos TGT requests.
Once an attacer obtains a computer certificate by abusing Active Directory Certificate Services in combination with PetitPotam, the next step would be to leverage the certificate for malicious purposes.
One way of doing this is to request a Kerberos Ticket Granting Ticket using a tool like Rubeus.
This request will generate a 4768 event with some unusual fields depending on the environment.
This analytic will require tuning, we recommend filtering Account_Name to the Domain Controller computer accounts.

Log source

product

windows

service

security

definition

The advanced audit policy setting "Account Logon > Kerberos Authentication Service" must be configured for Success/Failure

Detection

selection:
    EventID: 4768
    TargetUserName|endswith: '$'
    CertThumbprint|contains: '*'
filter_local:
    IpAddress: '::1'
filter_thumbprint:
    CertThumbprint: ''
condition: selection and not 1 of filter_*

False positives (as the rule lists them)

• False positives are possible if the environment is using certificates for authentication. We recommend filtering Account_Name to the Domain Controller computer accounts.

Tags

• attack.credential-access
• attack.t1187

MITRE ATT&CK ids this rule names

• T1187

References

• https://github.com/topotam/PetitPotam
• https://isc.sans.edu/forums/diary/Active+Directory+Certificate+Services+ADCS+PKI+domain+admin+vulnerability/27668/
• https://github.com/splunk/security_content/blob/88d689fe8a055d8284337b9fad5d9152b42043db/detections/endpoint/petitpotam_suspicious_kerberos_tgt_request.yml

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security/win_security_petitpotam_susp_tgt_request.yml