In a Pass-the-Hash or PtH attack, a threat actor steals a password and without decoding it, reuses it to manipulate an authentication system into creating a new authenticated session on the same network.
To carry out a pass the hash attack, the threat actor first captures the hashes from the targeted networking using certain hash dumping tools.
Then they use a pass the hash tool to lace the captured hashes on a Local Security. This often tricks a Window’s authentication system into considering that the malicious actor’s endpoint is that of the genuine user. This way, it will pass the required credentials when the attacker attempts to access the target network. And they don’t need the real password to do that.
PTH attacks leverage the authentication protocol, as the passwords have remained static for all session until it is rotated. Threat actors commonly capture hashes by scraping the active memory of a system and other tools.
While PTH attacks commonly occur in Windows-based systems, Linux, UNIX, and other platforms are not immune to this attack.
In Windows, PTH leverages SSO or Single Sign-On through NT Lan Manager NTLM, Kerberos, and other authentication processes. Whenever a password is created on a Windows system, it is often hashed and stored in the SAM (Security Accounts Manager), LSASS (Local Security Authority Subsystem) process memory, the Credential Manager store, and an ntds. dit database in Active Directory, or elsewhere.
Therefore, when you log into a Windows workstation or server, you leave behind your passwords.
How to Deal with Pass the Hash Attack?
To make a PtH attack successful, an attacker has to gain local administrative access on a system (PC) to capture the hash. Once the perpetrator gets into the system, they can meet their purpose easily, stealing more passwords.
Incorporating the following security practices can help eliminate, or at least reduce the impact of a Pass the Hash attack:
Having the least Privilege Security System:
It can reduce the possibility, and minimize the effect of a PTH attack, by minimizing a threat actor’s capability to get privileged access and permissions. Removing needless admin rights will be a long term solution to minimize the risk of PTH and many other security threats.
Implying Password Management Solutions:
Make sure to rotate your passwords frequently. You can automate password rotation after each privileged session. It will help you block PTH attacks.
Separating Privileged and Non-Privileged Accounts:
In this practice, different types of non-privileged accounts and privileged accounts are separated. It can minimize the attacker’s reach to the administrator accounts and thereby, minimize the risk for compromise, as well as the risk for lateral activity.