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1. #ALL THAT REMAINS PART 1 PASSWORD HOW TO#
2. #ALL THAT REMAINS PART 1 PASSWORD FULL#
3. #ALL THAT REMAINS PART 1 PASSWORD CODE#
4. #ALL THAT REMAINS PART 1 PASSWORD OFFLINE#
5. #ALL THAT REMAINS PART 1 PASSWORD WINDOWS#

Diving into wdigest.dll (and a little lsasrv.dll) With the debugger attached, let’s dig into WDigest. If at this point you find that symbols are not processed correctly, a. With the EPROCESS address identified ( ffff9d01325a7080 above), we can request that our debug session is switched to the lsass process context:Ī simple lm will show that we now have access to the WDigest DLL memory space: With a kernel debugger attached, we need to grab the EPROCESS address of the lsass process, which is found with the !process 0 0 lsass.exe command:

#ALL THAT REMAINS PART 1 PASSWORD HOW TO#

If you have never attached WinDBG to the kernel before, check out one of my previous posts on how to go about setting up a kernel debugger here. Instead we’ll have to attach to the kernel and switch over to the lsass process from Ring-0.

#ALL THAT REMAINS PART 1 PASSWORD WINDOWS#

Unfortunately in this case this isn’t going to be just as simple as attaching WinDBG to lsass, as pretty quickly you’ll see Windows grind to a halt before warning you of a pending reboot.

When reversing an OS component, I usually like to attach a debugger and review how it interacts with the OS during runtime. WDigest credential caching was of course enabled by default up until Windows Server 2008 R2, after which caching of plain-text credentials was disabled. So as mentioned, in this post we will look at is WDigest, arguably the feature that Mimikatz became most famous for. So, how does this “sekurlsa::wdigest” magic actually work? Thanks to Mimikatz, Benjamin Delpy and Vincent Le Toux for their awesome work. This effort should become more apparent as you see undocumented structures which are suddenly revealed when browsing through code.

#ALL THAT REMAINS PART 1 PASSWORD CODE#

Note: This post uses Mimikatz source code heavily as well as the countless hours dedicated to it by its developer(s). To finish off the post I will also explore some additional methods of loading arbitrary DLL’s within lsass, which can hopefully be combined with the code examples demonstrated.

#ALL THAT REMAINS PART 1 PASSWORD FULL#

This will mean disassembly and debugging, but hopefully by the end you will see that while its difficult to duplicate the amount of effort that has gone into Mimikatz, if your aim is to only use a small portion of the available functionality, it may be worth crafting a custom tool based on the Mimikatz source code, rather than opting to take along the full suite. Specifically, looking at how cleartext credentials are actually cached in lsass, and how they are extracted out of memory with "sekurlsa::wdigest". So over a few posts I wanted to change this and explore some of its magic, starting with where it all began…. I’ve been toying with the idea of stripping down Mimikatz for certain engagements (mainly those where exfiltrating a memory dump isn’t feasible or permitted), but it has been bugging me for a while that I’ve spent so long working with a tool that I’ve rarely reviewed low-level.

And while some security vendors are monitoring for process interaction with lsass, many more have settled on attempting to identify Mimikatz itself.

This being said, Mimikatz is a tool that is carried along with most post-exploitation toolkits in one form or another. And with security vendors reducing and monitoring the attack surface of common tricks often faster than we can discover fresh methods, knowing how a particular technique works down to the API calls can offer a lot of benefits when avoiding detection in well protected environments.

#ALL THAT REMAINS PART 1 PASSWORD OFFLINE#

Through my many online and offline rants conversations, people likely know by now my thoughts on RedTeam understanding their tooling beyond just executing a script. Essentially, execute Mimikatz on a host, and if the environment has any maturity at all you’re likely to be flagged. And of course with the success of Mimikatz over the years, BlueTeam are now very adept at detecting its use in its many forms. If you have ever looked at the effort that goes into Mimikatz, this is no easy task, with all versions of Windows x86 and 圆4 supported (and more recently, additions to support Windows on ARM arch). Of course this is due to the fact that with each new security control introduced by Microsoft, GentilKiwi always has a trick or two up his sleeve. We’ve packed it, we’ve wrapped it, we’ve injected it and powershell’d it, and now we’ve settled on feeding it a memory dump, and still Mimikatz remains the tool of choice when extracting credentials from lsass on Windows systems. « Back to home Exploring Mimikatz - Part 1 - WDigest