detecting-golden-ticket-attacks-in-kerberos-logs

name	detecting-golden-ticket-attacks-in-kerberos-logs
description	Detect Golden Ticket attacks in Active Directory by analyzing Kerberos TGT anomalies including mismatched encryption types, impossible ticket lifetimes, non-existent accounts, and forged PAC signatures in domain controller event logs.
domain	cybersecurity
subdomain	threat-hunting
tags	["threat-hunting","golden-ticket","kerberos","active-directory","mitre-t1558-001","credential-abuse"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["DE.CM-01","DE.AE-02","DE.AE-07","ID.RA-05"]
mitre_attack	["T1046","T1057","T1082","T1083","T1003"]
source	https://github.com/mukul975/Anthropic-Cybersecurity-Skills
source_commit	04450304b12645cb2b974ab96d28c0664758a88d

Detecting Golden Ticket Attacks in Kerberos Logs

When to Use

• When KRBTGT account hash may have been compromised via DCSync or NTDS.dit extraction
• When hunting for forged Kerberos tickets used for persistent domain access
• After incident response reveals credential theft at the domain level
• When investigating impossible logon patterns (users logging in from multiple locations simultaneously)
• During post-breach assessment to determine if Golden Tickets are in use

Prerequisites

• Windows Security Event IDs 4768, 4769, 4771 on domain controllers
• Kerberos policy configuration knowledge (max ticket lifetime, encryption types)
• Domain controller audit policy enabling Kerberos Service Ticket Operations
• SIEM with ability to correlate Kerberos events across multiple DCs

Workflow

1. Monitor TGT Requests (Event 4768): Track Kerberos authentication service requests. Golden Tickets bypass the AS-REQ/AS-REP exchange entirely, so the absence of 4768 before 4769 is suspicious.
2. Detect Encryption Type Anomalies: Golden Tickets often use RC4 (0x17) encryption. If your domain enforces AES (0x12), any RC4 TGT is a red flag. Monitor TicketEncryptionType in Event 4769.
3. Check Ticket Lifetime Anomalies: Default Kerberos TGT lifetime is 10 hours with 7-day renewal. Golden Tickets can be forged with 10-year lifetimes. Detect tickets with durations exceeding policy.
4. Hunt for Non-Existent SIDs: Golden Tickets can include arbitrary SIDs (including non-existent accounts or groups). Correlate TGS requests against known AD SID inventory.
5. Detect TGS Without Prior TGT: When a service ticket (4769) appears without a preceding TGT request (4768) from the same IP/account, this may indicate a pre-existing Golden Ticket.
6. Monitor KRBTGT Password Age: Track when KRBTGT was last reset. If KRBTGT hash hasn't changed since a known compromise, Golden Tickets from that period remain valid.
7. Validate PAC Signatures: With KB5008380+ and PAC validation enforcement, domain controllers reject forged PACs. Monitor for Kerberos failures indicating PAC validation errors.

Detection Queries

Splunk -- RC4 Encryption in Kerberos TGS

index=wineventlog EventCode=4769
| where TicketEncryptionType="0x17"
| where ServiceName!="krbtgt"
| stats count by TargetUserName ServiceName IpAddress TicketEncryptionType Computer
| where count > 5
| sort -count

Splunk -- TGS Without Prior TGT

index=wineventlog (EventCode=4768 OR EventCode=4769)
| stats earliest(_time) as first_tgt by TargetUserName IpAddress EventCode
| eventstats earliest(eval(if(EventCode=4768, first_tgt, null()))) as tgt_time by TargetUserName IpAddress
| where EventCode=4769 AND (isnull(tgt_time) OR first_tgt < tgt_time)
| table TargetUserName IpAddress first_tgt tgt_time