Dumping and Cracking mscash - Cached Domain Credentials
Last updated
Last updated
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.
Note that in meterpreter session, hashdump only dumps the local SAM account hashes:
To dump cached domain credentials in mscash format, use a post exploitation module cachedump
:
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:
Once the hives are retrieved, they can can be pulled back to kali linux to extract the hashes:
To crack mscache with hashcat, it should be in the following format:
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:
Let's try cracking it with hashchat now:
This can be seen via regedit (running with SYSTEM privileges) in the following key:
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: