Category: Cracking

Did I just rickroll you via password hashes? well yeah, I did and I refused to apologize. This post took me a day to write up and unfortunately you have to deal with the consequences. So, what happens to all the password hashes that get cracked by john? Well, they get stored in a file called john.pot. You can use locate on your system to find this but it is usually located in /root/.john/john.pot. If you’re trying to crack a hash but are getting an error message then it is likely you have already cracked it. Deleted the john.pot file or remove the line with the cracked has in order to re-crack the file.

MD4 hashes are outdated but you would be surprised to see how many organizations still use broken and outdated cryptographic algorithms. MD4 is a cryptographically broken encryption cipher originally developed by Ronal Rivest and first published in 1990. The syntax below shows you how to crack passwords encrypted with MD4 hashing algorithms.

What’s that? no secret is safe? Well if you use a crappy password and someone is able to obtain your password hash then you aren’t far from the truth. have you considered doing a password audit of your employee’s passwords to ensure they are secure? Maybe now is a good time. The syntax below shows how you can crack Whirlpool hashes. Whirlpool is a broken cryptographic algorithm designed by Vincent Rijmen and was first published in 2000.

Where did this hash come from? never mind, I’m sure our friend John can dispatch it fairly quickly. SHA256 is another cryptographically broken hashing algorithm that was developed by the National Security Agency (it’s almost as if they were designing them to fail).

As mentioned earlier, John The Ripper can crack a variety of password hashes. The example below shows how you can crack an MD5 hash. An MD5 Hash or MD5 message-digest algorithm is cryptographically broken but still commonly use having a function that produces a 128-bit hash value. MD5 was originally designed by Ronal Rivest in 1991 as a method of replacing MD4 hashes. I used the following syntax to crack the MD5 hash.

The next hash that somehow managed to sneak its way into my directory is a SHA1 hash. SHA1 is a cryptographically broken encryption cipher that was originally designed by the National Security Agency. It was initially released in 1993 and produces a 160-bit hash. The following syntax shows how you can crack a SHA1 hash.

John The Ripper will automatically attempt to identify the hashes that you give him. However, this can be prone to error. Fortunately, there are plenty of tools out there that you can use to identify password hash types. One such tool is hash-identifier which will come preinstalled or should be installable via your package manager or via cloning it from GitHub. To run the tool you simply type the name and then it will ask you to submit your hash. It will then spit out a list of hash types in the order of likelihood. Then you can use that information to manually tell John what type of hash you want to crack.

John has a number of different password hash cracking modes. These various modes can be used to crack password hashes in different ways. If one method of cracking a password hash didn’t work, then you could try a different mode.