After gaining a footing in the network, an adversary's methods change to compromising more systems and securing the rights required to execute their purpose. Pass-the-Hash Attack is a lateral movement and credential theft technique in which an attacker exploits the NTLM authentication protocol to authenticate as a user without ever gaining the account's plaintext password. Because the attacker uses the password hash, which typically only changes when the password is updated, the adversary has plenty of opportunity to perform a pass-the-hash attack to exploit the compromised account.features that make one Best EDR Solution more effective than another.
Pass-the-Hash Attack (PtH) Definition
In a (PtH) Pass-the-Hash attack, an attacker EDR steals a password hash (the password characters) and uses it to gain lateral access to other networked systems and authenticate users. The threat actor does not need to decrypt the hash in order to obtain a plain text password using this method. Because the password hash remains static for each session until the password is rotated, A pass-the-hash attack takes advantage of the authentication protocol. Attackers frequently get hashes using techniques like active memory skimming.
An attacker can execute a Pass-the-Hash attack on UNIX, Linux, and any other platforms, although they are more common on Windows devices. PtH makes use of NT Lan Manager (NTLM), Kerberos, Single Sign-On (SS0) for Windows, as well as other authentication protocols. When a password is generated in Windows, it is hashed and saved in the Security Accounts Manager (SAM), Active Directory ntds.dit database, the Local Security Authority Subsystem (LSASS) process memory, the Credential Manager (CredMan) store, or somewhere else. When a user signs into a Windows workstation or server, they leave their password credentials behind.
How does a pass-the-hash attack work?
In a pass-the-hash attack, the attacker generally gains network access via a social engineering technique like phishing, in which a cybercriminal exploits another person's emotions, such as fear, empathy, or greed, to persuade them to share personal information or download a malicious file.
Once the attacker has accessed the user's account, they employ various tools and techniques to scrape active memory for data that will lead them to the hashes.
The attacker can get complete system access by combining with one or more usable hashes in a pass-the-hash attack, thus permitting lateral network movement. As the attacker moves from application to application impersonating the user, they engage in hash harvesting — accumulating additional hashes throughout the system that can be utilized to access more network areas, add account privileges, target a compromised account, and create backdoors and other gateways to go ahead with future access.
Who is vulnerable to a pass-the-hash attack?
A Pass-the-hash attack is more vulnerable, especially for Windows server clients and organizations that use Windows New Technology LAN Manager (NTLM).
NTLM is a collection of Microsoft security protocols that authenticate users' identities while also ensuring the integrity and confidentiality of their activity. NTLM is essentially an SSO tool that uses a challenge-response protocol to validate the user's identity without asking them to provide a password, a process known as NTLM authentication.
NTLM was vulnerable to various security flaws relating to password hashing and salting. Passwords stored on the server and domain controller in NTLM are not "salted," meaning a random string of characters is not punched into the hashed password to protect it from cracking techniques. This means adversaries with a password hash can authenticate a session without knowing the original password.
The cryptography used by NTLM also fails to take advantage of current breakthroughs in algorithms and encryption that considerably improve security capabilities.
While Kerberos replaced NTLM as the primary authentication mechanism in Windows 2000 and subsequent Active Directory (AD) domains, it is still supported in all Windows systems for backward compatibility with older clients and servers. Computers running Windows 95, Windows 98, or Windows NT 4.0 will utilize the NTLM protocol for network authentication with a Windows 2000 domain. Meanwhile, Windows 2000 computers will use NTLM to authenticate servers running Windows NT 4.0 or older, as well as to access resources in Windows 2000 or earlier domains. Local logins with non-domain controllers are likewise authenticated via NTLM.
How to Prevent a Pass-the-Hash Attack
To carry out a pass-the-hash attack, the attacker must first get local administrative access to a computer in order to lift the hash. The attacker can even be able to pave laterally, getting access to more credentials and increasing privileges along the way once the attacker has acquired a foothold in a pass-the-hash attack. The effects of a pass-the-hash attack can be reduced, or at the very least diminished, by using the security best practices listed below:
Least Privilege Security Model
Reduces an attacker's ability to escalate privileged access and permissions, limiting the chances and severity of a pass-the-hash attack. Removing unnecessary admin privileges will help to reduce the threat surface for a pass-the-hash attack and other forms of attacks.
Password Management Solutions
Password rotation on a regular basis (and/or after a known credential compromise) can reduce the amount of time a stolen hash in a pass-the-hash attack remains valid. You may entirely prevent a pass-the-hash attack and exploits that rely on password reuse by automating password rotation to take place after each privileged session.
Separation of Privileges
Separating privileged and non-privileged accounts can limit the scope of administrator account activity with a pass-the-hash attack, lowering the risks of compromise and opportunities for lateral movement.
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FAQ Section
Pass-the-Hash attacks can be challenging to search and detect, because of their ability to remain stealthy. Ensure to have strong security measures such as comprehensive monitoring systems, threat detection techniques, and incident prevention systems.
Pass-the-Hash attacks often target systems with weak security configurations, unpatched vulnerabilities, or compromised user accounts.
Pass-the-Hash attacks pose significant security risks, enabling attackers to navigate through networks, masquerade as legitimate users, and potentially access sensitive data or critical system files.
Pass-the-Hash attacks frequently focus on privileged accounts, such as administrative or domain controller accounts. These accounts grant substantial access to crucial systems and sensitive data.