Pass the Hash
|Pass the Hash|
|System Requirements||Requires Microsoft Windows as target system|
|Data Sources||Authentication logs|
|Contributors||Travis Smith, Tripwire|
Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash. In this technique, valid password hashes for the account being used are captured using a Credential Access technique. Captured hashes are used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems.
Windows 7 and higher with KB2871997 require valid domain user credentials or RID 500 administrator hashes.1
- The APT1 group is known to have used pass the hash.2
- APT28 has used pass the hash for lateral movement.3
- APT29 used Kerberos ticket attacks for lateral movement.4
- Cobalt Strike can perform pass the hash.5
SEKURLSA::Pthmodule can impersonate a user, with only a password hash, to execute arbitrary commands.6
- Pass-The-Hash Toolkit can perform pass the hash.2
Monitor systems and domain logs for unusual credential logon activity. Prevent access to Valid Accounts. Apply patch KB2871997 to Windows 7 and higher systems to limit the default access of accounts in the local administrator group.
Enable pass the hash mitigations to apply UAC restrictions to local accounts on network logon. The associated Registry key is located
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LocalAccountTokenFilterPolicy Through GPO: Computer Configuration > [Policies] > Administrative Templates > SCM: Pass the Hash Mitigations: Apply UAC restrictions to local accounts on network logons.7
Limit credential overlap across systems to prevent the damage of credential compromise and reduce the adversary's ability to perform Lateral Movement between systems. Ensure that built-in and created local administrator accounts have complex, unique passwords. Do not allow a domain user to be in the local administrator group on multiple systems.
Audit all logon and credential use events and review for discrepancies. Unusual remote logins that correlate with other suspicious activity (such as writing and executing binaries) may indicate malicious activity. NTLM LogonType 3 authentications that are not associated to a domain login and are not anonymous logins are suspicious.
- National Security Agency/Central Security Service Information Assurance Directorate. (2013, December 16). Spotting the Adversary with Windows Event Log Monitoring. Retrieved November 12, 2014.
- Mandiant. (n.d.). APT1 Exposing One of China’s Cyber Espionage Units. Retrieved July 18, 2016.
- Anthe, C. et al. (2015, October 19). Microsoft Security Intelligence Report Volume 19. Retrieved December 23, 2015.
- Dunwoody, M. and Carr, N.. (2016, September 27). No Easy Breach DerbyCon 2016. Retrieved October 4, 2016.
- Cobalt Strike. (2017, December 8). Tactics, Techniques, and Procedures. Retrieved December 20, 2017.
- Metcalf, S. (2015, November 13). Unofficial Guide to Mimikatz & Command Reference. Retrieved December 23, 2015.
- NSA IAD. (2017, January 24). Secure-Host-Baseline/Windows/Group Policy Templates/en-US/SecGuide.adml. Retrieved December 18, 2017.