Adversaries may abuse a valid Kerberos ticket-granting ticket (TGT) or sniff network traffic to obtain a ticket-granting service (TGS) ticket that may be vulnerable to Brute Force.(Citation: Empire InvokeKerberoast Oct 2016)(Citation: AdSecurity Cracking Kerberos Dec 2015)
Service principal names (SPNs) are used to uniquely identify each instance of a Windows service. To enable authentication, Kerberos requires that SPNs be associated with at least one service logon account (an account specifically tasked with running a service(Citation: Microsoft Detecting Kerberoasting Feb 2018)).(Citation: Microsoft SPN)(Citation: Microsoft SetSPN)(Citation: SANS Attacking Kerberos Nov 2014)(Citation: Harmj0y Kerberoast Nov 2016)
Adversaries possessing a valid Kerberos ticket-granting ticket (TGT) may request one or more Kerberos ticket-granting service (TGS) service tickets for any SPN from a domain controller (DC).(Citation: Empire InvokeKerberoast Oct 2016)(Citation: AdSecurity Cracking Kerberos Dec 2015) Portions of these tickets may be encrypted with the RC4 algorithm, meaning the Kerberos 5 TGS-REP etype 23 hash of the service account associated with the SPN is used as the private key and is thus vulnerable to offline Brute Force attacks that may expose plaintext credentials.(Citation: AdSecurity Cracking Kerberos Dec 2015)(Citation: Empire InvokeKerberoast Oct 2016) (Citation: Harmj0y Kerberoast Nov 2016)
This same behavior could be executed using service tickets captured from network traffic.(Citation: AdSecurity Cracking Kerberos Dec 2015)
Cracked hashes may enable Persistence, Privilege Escalation, and Lateral Movement via access to Valid Accounts.(Citation: SANS Attacking Kerberos Nov 2014)
View in MITRE ATT&CK®Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
---|---|---|---|---|---|
DEF-SECA-E3 | Security Alerts | Technique Scores | T1558.003 | Kerberoasting |
Comments
Microsoft Defender security alerts explain the suspicious activities detected by Defender for Identity sensors on your network, and the actors and computers involved in each threat. Alert evidence lists contain direct links to the involved users and computers, to help make your investigations easy and direct.
Defender security alerts are divided into the following categories or phases, like the phases seen in a typical cyber-attack kill chain. Learn more about each phase, the alerts designed to detect each attack, and how to use the alerts to help protect your network using the following links:
Reconnaissance and discovery alerts
Persistence and privilege escalation alerts
Credential access alerts
Lateral movement alerts
Other alerts
License: A Microsoft 365 security product license entitles customer use
of Microsoft Defender XDR.
References
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