Kerberoasting

T1558.003

Sub-technique of T1558 Steal or Forge Kerberos Tickets.View on attack.mitre.org

About this technique

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.

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).

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). 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.

This same behavior could be executed using service tickets captured from network traffic.

Cracked hashes may enable Persistence, Privilege Escalation, and Lateral Movement via access to Valid Accounts.

Detection rules24

Rules on DetectionCode tagged with T1558.003.

Sigma16

Splunk8

RuleTypeRiskData source
Kerberoasting spn request with RC4 encryptionTTPNULLWindows Event Log Security 4769
Rubeus Command Line ParametersTTPNULLSysmon EventID 1, Windows Event Log Security 4688, CrowdStrike ProcessRollup2
ServicePrincipalNames Discovery with PowerShellTTPNULLPowershell Script Block Logging 4104
ServicePrincipalNames Discovery with SetSPNTTPNULLSysmon EventID 1, Windows Event Log Security 4688, CrowdStrike ProcessRollup2
Unusual Number of Kerberos Service Tickets RequestedAnomalyNULLWindows Event Log Security 4769
Windows PowerView Kerberos Service Ticket RequestTTPNULLPowershell Script Block Logging 4104
Windows PowerView SPN DiscoveryTTPNULLPowershell Script Block Logging 4104
Windows Process With NetExec Command Line ParametersTTPNULLWindows Event Log Security 4688, Sysmon EventID 1, CrowdStrike ProcessRollup2

Groups3

Software6

Campaigns3

Procedure examples12

Groups3

Used byProcedure example
GroupFIN7

FIN7 has used Kerberoasting PowerShell commands such as, `Invoke-Kerberoast` for credential access and to enable lateral movement.

GroupIndrik Spider

Indrik Spider has conducted Kerberoasting attacks using a module from GitHub.

GroupWizard Spider

Wizard Spider has used Rubeus, MimiKatz Kerberos module, and the Invoke-Kerberoast cmdlet to steal AES hashes.

Software6

Used byProcedure example
ToolBrute Ratel C4

Brute Ratel C4 can decode Kerberos 5 tickets and convert it to hashcat format for subsequent cracking.

ToolEmpire

Empire uses PowerSploit's Invoke-Kerberoast to request service tickets and return crackable ticket hashes.

ToolImpacket

Impacket modules like GetUserSPNs can be used to get Service Principal Names (SPNs) for user accounts. The output is formatted to be compatible with cracking tools like John the Ripper and Hashcat.

ToolPowerSploit

PowerSploit's Invoke-Kerberoast module can request service tickets and return crackable ticket hashes.

ToolRubeus

Rubeus can use the `KerberosRequestorSecurityToken.GetRequest` method to request kerberoastable service tickets.

ToolSILENTTRINITY

SILENTTRINITY contains a module to conduct Kerberoasting.

Campaigns3

Used byProcedure example
CampaignLeviathan Australian Intrusions

Leviathan used Kerberoasting techniques during Leviathan Australian Intrusions.

CampaignOperation Wocao

During Operation Wocao, threat actors used PowerSploit's `Invoke-Kerberoast` module to request encrypted service tickets and bruteforce the passwords of Windows service accounts offline.

CampaignSolarWinds Compromise

During the SolarWinds Compromise, APT29 obtained Ticket Granting Service (TGS) tickets for Active Directory Service Principle Names to crack offline.

References7

  1. AdSecurity Cracking Kerberos Dec 2015 Open source
    Metcalf, S. (2015, December 31). Cracking Kerberos TGS Tickets Using Kerberoast – Exploiting Kerberos to Compromise the Active Directory Domain. Retrieved March 22, 2018.
  2. Empire InvokeKerberoast Oct 2016 Open source
    EmpireProject. (2016, October 31). Invoke-Kerberoast.ps1. Retrieved March 22, 2018.
  3. Harmj0y Kerberoast Nov 2016 Open source
    Schroeder, W. (2016, November 1). Kerberoasting Without Mimikatz. Retrieved September 23, 2024.
  4. Microsoft Detecting Kerberoasting Feb 2018 Open source
    Bani, M. (2018, February 23). Detecting Kerberoasting activity using Azure Security Center. Retrieved March 23, 2018.
  5. Microsoft SPN Open source
    Microsoft. (n.d.). Service Principal Names. Retrieved March 22, 2018.
  6. Microsoft SetSPN Open source
    Microsoft. (2010, April 13). Service Principal Names (SPNs) SetSPN Syntax (Setspn.exe). Retrieved March 22, 2018.
  7. SANS Attacking Kerberos Nov 2014 Open source
    Medin, T. (2014, November). Attacking Kerberos - Kicking the Guard Dog of Hades. Retrieved March 22, 2018.

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