With over 20 years as a professional in Information Technology, I’m always looking at new methodologies. However, I’m also looking at the ways things haven’t changed.
For as long as I remember, privileged account exploitation has always been at the center of targeted cyber attacks. This provides InfoSec Professionals with a constant pattern of events to look for on their networks.
In typical fashion, attackers penetrate the network perimeter using phishing attacks or attacks on mobile devices, hijack credentials and use them to move laterally throughout the network, taking additional credentials and escalating privileges along the way.
During my time as a Penetration Tester, combining privileged accounts with attacks on the Kerberos authentication in Windows domains was a method I always employed, in hopes of compromising the entire network. In fact, my team used to joke that lunch wouldn’t be served until we had “Domain Admin”. During such attacks, my team would target domain administrator privileges, which provide unrestricted access and control of the IT landscape. Armed with these privileges, my team could manipulate Domain Controllers (and Active Directory) and generate Kerberos tickets to obtain unauthorized access. Our ultimate goal was the “Golden Ticket”! That’s the ticket that gives us 10 years of unfettered access.
In order to successfully collect one of these tickets, the four things necessary to formulate one is:
· the account name of a domain administrator
· the domain name
· the SID for the domain
· the password hash of the krbtgt user from the Domain Controller
The good news is that Golden Ticket Attacks are particularly noisy, both in system logs and on the network. With the ability to perform deep packet inspection on Kerberos and DCE-RPC logs, this gives users of PacketSled the ability to look for indicators of these attacks across their entire network, instead of searching through system logs which are often dispersed and not centrally stored while attempting to piece together the pattern for themselves
In particular, Golden Ticket Attacks require a particular DCE-RPC command on the network, defined as, “DRSGetNCChanges”. This command obtains updates for a specified naming context (NC = partition of the AD database), typically between domain controllers. This behavior is particularly useful, as knowing that this data would not be transferred between a workstation and a domain controller would be anomalous.
Now, how do you get visibility into these attacks from a central point? Well, deploying a PacketSled sensor to establish a perimeter has never been easier. We have an IR deployment package that can have you up and running in minutes. Provide a SPAN/TAP feed to our sensor(s) and you have perimeter network visibility when you need it most.
Using this approach to develop the security detection moves the security controls from making decisions based on circumstantial, atomic elements and moves towards being more contextual in nature. This can greatly reduce the false-positive rate and make notifications more actionable.
At PacketSled, our researchers are continually pushing the boundaries of using our IRES-based security platform to provide greater value in security notifications. We do so by not just notifying InfoSec Professionals with alarms of potentially malicious behavior, but putting the context of those events in their hands as quickly as possible.
Let us show you the value of PacketSled network visibility tools. To arrange a product demonstration or talk IR strategies give us a call.
Posted on February 21, 2017