P-ppk-crack will try to brute force PuTTY generated private key passphrases.
The source code is based on putty svn version (actually on plink), check http://chiark.greenend.org.uk/~sgtatham/putty/licence.html. This is just a quick-hack, which demonstrates that you should use a strong passphrase for your private key!
Example using John the ripper v1.7.2
Microsoft Windows [Version 6.0.6000]
Copyright (c) 2006 Microsoft Corporation. Alle Rechte vorbehalten.
C:>jo-hn -stdout -incremental | p-ppk-crack password.ppk
p-ppk-crack v0.5 made by firstname.lastname@example.org - PuTTY private key cracker
trying 65808 keys/s, # of tested keys: 1711001.
This test ran inside a VMWare machine, the host system is W2K Pro. On the host system the performance was arround 35’000 k/s, looks like Vista is quite faster…