In this tutorial we will show you how to create a list of MD5 password hashes and crack them using hashcat.
We will perform a dictionary attack using the rockyou wordlist on a Kali Linux box.
CREATING A LIST OF MD5 HASHES TO CRACK
To create a list of MD5 hashes, we can use md5sum command.
The full command we want to use is:
echo -n "Password1" | md5sum | tr -d " -" >> hashes
Here we are piping a password to md5sum so a hash is produced. Unnecessary output is then stripped and it is stored in a file in a file called “hashes”.
“echo -n ‘Password1′” is used to print the phrase “Password1”. The -n portion removes the new line added to the end of “Password1”. This is important as we don’t want the new line characters to be hashed with our password.
The part “tr –d ‘ -‘ “ removes any characters that are a space or hyphen from the output like so:
Before:
# echo -n "Password1" | md5sum 2ac9cb7dc02b3c0083eb70898e549b63 -
After:
# echo -n "Password1" | md5sum | tr -d " -" 2ac9cb7dc02b3c0083eb70898e549b63
For demonstration purposes, we’ll create multiple MD5 hashes containing different strength passwords and output them to a file called hashes:
echo -n "Password1" | md5sum | tr -d " -" >> hashes echo -n "HELLO" | md5sum | tr -d " -" >> hashes echo -n "MYSECRET" | md5sum | tr -d " -" >> hashes echo -n "Test1234" | md5sum | tr -d " -" >> hashes echo -n "P455w0rd" | md5sum | tr -d " -" >> hashes echo -n "GuessMe3" | md5sum | tr -d " -" >> hashes echo -n "S3CuReP455Word" | md5sum | tr -d " -" >> hashes echo -n "HighlyUnlik3lyToB3Cr4ck3d…" | md5sum | tr -d " -" >> hashes
Once you have run these commands will look something like this:
# cat hashes 2ac9cb7dc02b3c0083eb70898e549b63 eb61eead90e3b899c6bcbe27ac581660 958152288f2d2303ae045cffc43a02cd 2c9341ca4cf3d87b9e4eb905d6a3ec45 75b71aa6842e450f12aca00fdf54c51d 98bffa1e0b3872aa0813b0a62a2003ab b5af0b804ff7238bce48adef1e0c213f 5a53193b4cca4ccdabf3ccb1fa514162
If you already have a list of words then the following bash script can be used to automate the MD5 generation, reading each line in a file, then generating a file off the resulting hashes. Replace ‘wordlist’ with the file path of your word list.
for i in $(cat wordlist); do echo -n "$i"| md5sum | tr -d " -" >> hashes; done
If you do not have md5sum on your machine, you can copy and paste the hashes above and save it in a file called “hashes”. If you want to hash different passwords than the ones above and you don’t have md5sum installed, you can use MD5 generators online such as this one.
RUNNING HASHCAT TO CRACK MD5 HASHES
Now we can start using hashcat with the rockyou wordlist to crack the MD5 hashes. The rockyou wordlist comes pre-installed with Kali. If you are not using Kali you can use another wordlist, or download it from here.
The command to start our dictionary attack on the hashes is:
hashcat –m 0 hashes /usr/share/wordlists/rockyou.txt
| Argument | Function |
| -m 0 | Tells hashcat which mode to use. 0 is MD5. |
| Hashes | Our file containing the our MD5 password hashes. |
| /usr/share/wordlists/rockyou.txt | Points hashcat to the wordlist containing the passwords to hash and compare. |
When you run the command, you should get an output like below:
# hashcat -m 0 hashes /usr/share/wordlists/rockyou.txt Initializing hashcat v2.00 with 2 threads and 32mb segment-size... Added hashes from file hashes: 8 (1 salts) 2ac9cb7dc02b3c0083eb70898e549b63:Password1 eb61eead90e3b899c6bcbe27ac581660:HELLO 958152288f2d2303ae045cffc43a02cd:MYSECRET 75b71aa6842e450f12aca00fdf54c51d:P455w0rd 2c9341ca4cf3d87b9e4eb905d6a3ec45:Test1234 [s]tatus [p]ause [r]esume [b]ypass [q]uit => Input.Mode: Dict (/usr/share/wordlists/rockyou.txt) Index.....: 1/5 (segment), 3627099 (words), 33550339 (bytes) Recovered.: 5/8 hashes, 0/1 salts Speed/sec.: 9.90M plains, 9.90M words Progress..: 3627099/3627099 (100.00%) Running...: --:--:--:-- Estimated.: --:--:--:-- [s]tatus [p]ause [r]esume [b]ypass [q]uit => Input.Mode: Dict (/usr/share/wordlists/rockyou.txt) Index.....: 2/5 (segment), 3351795 (words), 33550340 (bytes) Recovered.: 5/8 hashes, 0/1 salts Speed/sec.: 16.43M plains, 16.43M words Progress..: 3351795/3351795 (100.00%) Running...: 00:00:00:01 Estimated.: --:--:--:-- ... [s]tatus [p]ause [r]esume [b]ypass [q]uit => Input.Mode: Dict (/usr/share/wordlists/rockyou.txt) Index.....: 5/5 (segment), 553095 (words), 5720149 (bytes) Recovered.: 5/8 hashes, 0/1 salts Speed/sec.: 9.23M plains, 9.23M words Progress..: 553095/553095 (100.00%) Running...: --:--:--:-- Estimated.: --:--:--:-- Started: Thu Jul 14 05:37:50 2016 Stopped: Thu Jul 14 05:37:53 2016
Towards the top of the output you can see the hashes that were cracked side-by-side with the plaintext password and hash.
From the output we can determine the following passwords we hashed were not in the rockyou wordlist:
- GuessMe3
- S3CuReP455Word
- HighlyUnlik3lyToB3Cr4ck3d
Unless told otherwise, any hash that hashcat cracks will be stored in a hashcat.pot file. This will be created in directory where you ran hashcat.
The contents of your “hashcat.pot” file from this tutorial should look like the following:
#cat hashcat.pot 2ac9cb7dc02b3c0083eb70898e549b63:Password1 eb61eead90e3b899c6bcbe27ac581660:HELLO 958152288f2d2303ae045cffc43a02cd:MYSECRET 75b71aa6842e450f12aca00fdf54c51d:P455w0rd 2c9341ca4cf3d87b9e4eb905d6a3ec45:Test1234
SUMMARY
This has been a basic tutorial on how to crack MD5 hashes using hashcat. We’ve MD5 hashed passwords and using hashcat, cracked five out of the total eight. The attack technique that we used within hashcat was a dictionary attack with the rockyou wordlist.
Chris Nadeau 