Use Alternate Authentication Material: Pass the Hash

Adversaries may "pass the hash" using stolen password hashes to move laterally within an environment, bypassing normal system access controls. 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]

ID: T1550.002
Sub-technique of:  T1550
Tactics: Defense Evasion, Lateral Movement
Platforms: Windows
Data Sources: Authentication logs
Defense Bypassed: System Access Controls
CAPEC ID: CAPEC-644
Contributors: Travis Smith, Tripwire
Version: 1.0
Created: 30 January 2020
Last Modified: 23 March 2020

Procedure Examples

Name Description
APT1

The APT1 group is known to have used pass the hash.[2]

APT28

APT28 has used pass the hash for lateral movement.[3]

APT32

APT32 has used pass the hash for lateral movement.[4]

Cobalt Strike

Cobalt Strike can perform pass the hash.[5]

CrackMapExec

CrackMapExec can pass the hash to authenticate via SMB.[6]

Empire

Empire can perform pass the hash attacks.[7]

HOPLIGHT

HOPLIGHT has been observed loading several APIs associated with Pass the Hash.[8]

Mimikatz

Mimikatz's SEKURLSA::Pth module can impersonate a user, with only a password hash, to execute arbitrary commands.[9][10]

Night Dragon

Night Dragon used pass-the-hash tools to gain usernames and passwords.[11]

Pass-The-Hash Toolkit

Pass-The-Hash Toolkit can perform pass the hash.[2]

PoshC2

PoshC2 has a number of modules that leverage pass the hash for lateral movement.[12]

Soft Cell

Soft Cell used dumped hashes to authenticate to other machines via pass the hash.[13]

Mitigations

Mitigation Description
Privileged Account Management

Limit credential overlap across systems to prevent the damage of credential compromise and reduce the adversary's ability to perform Lateral Movement between systems.

Update Software

Apply patch KB2871997 to Windows 7 and higher systems to limit the default access of accounts in the local administrator group.

User Account Control

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.[14]

User Account Management

Do not allow a domain user to be in the local administrator group on multiple systems.

Detection

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.

References