I have a client with a hacked IMAP-Account, and the attacker(s) made thousands of password-attempts, probably with a fixed set of passwords, from different IPs before they got in.

After successful password guessing I see 10-15 different IPs connecting and pushing out spams, simply killing that little ol' post-fix server :(. After flushing 440.000 mails from the queue and resetting all passwords to secure ones, Nr 5 lives, again!

My question:

  • What tool is used for distributed attacks on accounts / spam sending? i know about hydra & consorts, but I never saw a tool for botnet-like brute force. Are sources available somewhere?

Edit: changed brute-force to dictionary attack

  • 1
    Assuming you already have a botnet this doesn't seem like such a difficult attack to create. An actual brute-force would obviously be a bit trickier than just a dictionary or rainbow-tables, are you sure they really did a true brute force? Or do you only have hashes?
    – KnightOfNi
    Commented Jan 30, 2014 at 20:37
  • dictionary attack. Commented Jan 30, 2014 at 21:52

1 Answer 1


This might give you a little in-site into the process needed to perform this type of thing, http://du.nham.ca/blog/posts/2013/03/08/password-cracking-on-amazon-ec2/ it uses http://hashcat.net/oclhashcat-plus/ along with ec2 to perform circa 2320.9 million MD5 hashes per second, it's maybe not exactly what you looking for but it will certainly give you some pointers.

  • 1
    You refer to offline password cracking, which has nothing to do with the question.
    – ack__
    Commented Mar 2, 2014 at 15:03

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