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 attack 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 |
|---|---|---|---|---|---|
| azure_sentinel | Azure Sentinel | technique_scores | T1558.003 | Kerberoasting |
Comments
Azure Sentinel Analytics includes a "Potential Kerberoasting" query. Kerberoasting via Empire can also be detected using the Azure Sentinel Analytics "Powershell Empire cmdlets seen in command line" query.
References
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| microsoft_defender_for_identity | Microsoft Defender for Identity | technique_scores | T1558.003 | Kerberoasting |
Comments
This control's "Suspected Kerberos SPN exposure (external ID 2410)" alert is able to detect when an attacker use tools to enumerate service accounts and their respective SPNs (Service principal names), request a Kerberos service ticket for the services, capture the Ticket Granting Service (TGS) tickets from memory and extract their hashes, and save them for later use in an offline brute force attack.
Similarly its "Suspected AS-REP Roasting attack (external ID 2412)" alert is able to detect AS-REP Roasting sub-technique.
The accuracy of these alerts is unknown and therefore its score has been assessed as Partial.
References
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| azure_defender_for_app_service | Azure Defender for App Service | technique_scores | T1558.003 | Kerberoasting |
Comments
This control analyzes host data to detect execution of known malicious PowerShell PowerSploit cmdlets. This covers execution of this sub-technique via the Invoke-Kerberoast module, but does not address other procedures, and temporal factor is unknown, resulting in a Minimal score.
References
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| azure_ad_identity_secure_score | Azure AD Identity Secure Score | technique_scores | T1558.003 | Kerberoasting |
Comments
This control's "Modify unsecure Kerberos delegations to prevent impersonation" recommendation promotes running the "Unsecure Kerberos delegation" report that can identify accounts that have unsecure Kerberos delegation configured. Unsecured Kerberos delegation can lead to exposing account TGTs to more hosts resulting in an increased attack surface for Kerberoasting. Due to this control providing a recommendation its score is capped at Partial.
References
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