Pass the Hash Protections.
Copyright: Walt Disney Productions
Last week I attended the BSide LA hackers’ conference to discuss that passwords are secure. At first, some of the attendees scoffed at my claim. I then went on to explain that it’s the management of passwords and the way some IT administrators configure their networks that causes the insecurities. To that point, they agreed. However, the more persistent attendees brought up the “Pass the Hash” (PtH) attack as the reason why passwords will never be secure.
Not being as well verse on PtH as with other attacks, I needed to do a little research before I had an informed response.
A Pass-the-Hash (PtH) attack uses a technique in which an attacker captures the password hash value on one computer and then plays back the hash without ever knowing any passwords. Ultimately, the attacker gets access to network disks, memory, network domain controllers, and other servers to install drivers, applications, and execute applications.
For a hacker to start the attack, he/she first needs access to a computer on a network with administrator rights. This often can easily be accomplished if IT inadvertently assigned “Administration” rights to a User/employee (Note: most Users do not need Administrator rights). Because Users typically do a poor job of generating and managing their logon password, the hacker easily breaks in the User’s account. The administrative privileges allows the hacker to drill deeper into the network. Even if a complex password is used, if the employee writes it down on a sticky note it only takes a cell phone camera to capture the password and sell it on the internet.
The password hash is the key to the kingdom with superadmin rights. The hacker can do anything, and can bypass all the security barriers IT has installed. All operating systems, authentication protocol, even Kerberos, and smartcard logons are vulnerable. What’s worst, there’s no defense, but there are protections.
Hash authentication is not a bug, hole, or flaw that can be solved with a patch. Microsoft, Apple, and others claim they cannot stop the attack. Therefore, the best defense is stop worrying and fighting PtH. Instead, keep the hackers from getting in in the first place. Here are some simple ways to start protecting your network.
- Don’t allow every user or employee to have administrative rights
- Administrator passwords should have a short lifecycle
- Implement strong, complex password policies
- Of course, maintain strong and up-to-date antivirus, antimalware, firewalls, whitelists, etc.
- Don’t use Remote Desktop Protocol (RDP) or some other sort of interactive remote software to administrate computers
- Don’t allow or assign a superadmins. Instead, “delegate” just the rights an administrator needs and no more
- When and employee is finished for the day, they not only need to log out but power down the computer
How Power LogOn Addresses Pass the Hash
Pass the Hash is not a password authentication issue, but again an administration and system security issue. While Power LogOn cannot stop or prevent a PtH there are features within Power LogOn to make an unauthorized access more difficult.
- IT assigns complex passwords
- IT changes passwords more frequently in the background
- Users don’t generate, type or know their passwords
- Power LogOn can auto-shut down or log users off the network when their smartcard is removed
- PL does not store an “authenticator” in memory and therefore requires users to present their card every time they logon to an application or website while using PL SSO functionality
- If a thief stole a Windows users password or password hash it would not enable them to logon to Power Logon managed SSO applications or website
Again, currently there are no ways to stop a Pass the Hash attack. Access Smart does not claim that we can safeguard a company for such an attack. However, Power LogOn does add some barriers while keeping the logon process convenient for the user so they don’t circumvent cyber security. The best an IT administrator can do is put up enough barriers for a hacker that the time and effort to break into a computer and network is too great; especially when there are easier prey just around the corner.