Dump SAM file while system is running?

Question

I've exploited test machines using metasploit and was able to get the hashes from the SAM file; I've tried running commands as SYSTEM to get them but am unable to do so. I know you can get the hashes with C&A but want more of a portable solution.

Answer 1

It's not a permission issue – Windows keeps an exclusive lock on the SAM file (which, as far as I know, is standard behavior for loaded registry hives), so it is impossible for any other process to open it.

However, recent Windows versions have a feature called "Volume Shadow Copy", which is designed to create read-only snapshots of the entire volume, mostly for backups. The file locks are there to ensure data consistency, so they are unnecessary if a snapshot of the entire filesystem is made. This means that it is possible to create a snapshot of C:, mount it, copy your SAM file, then discard the snapshot.

How exactly to do this depends on your Windows version: XP needs an external program, Vista and 7 have vssadmin create shadow, and Server 2008 has the diskshadow command. The page Safely Dumping Hashes from Live Domain Controllers has more details on this process, as well as instructions and scripts.

Alternatively, there are tools such as samdump which abuse the LSASS process from various directions in order to extract all password hashes directly from memory. They might be much faster than VSS snapshots, but have a higher risk of crashing the system.

Finally, Google brings out this snippet, whose usefulness I cannot rate having never used metasploit myself:

meterpreter> use priv
meterpreter> hashdump

Answer 2

I have found the answer to my question. While grawity did give me a great answer nonetheless; I must say that I have finally found out how to do this with a simple tool.

I was able to dump my SAM file with simple administrative permissions on my Windows 7 x64 fully patched machine using fgdump. You can also use Cain to do this.