How to identify and crack a Double MD5 — md5(md5($pass)) hash

Double MD5 — md5(md5($pass)) is a raw / unsalted hash type. It is fast and typically unsalted, which makes weak passwords recoverable quickly on consumer GPU hardware. This page shows how to recognise it and the exact commands to attack it.

All identification runs locally in WebAssembly. The commands below write the hash to a local file on your machine — nothing is sent to this site.

Identifying the hash

The hash identifier on the home page detects Double MD5 — md5(md5($pass)) entirely in your browser — your hash is never uploaded. A typical example looks like this:

a936af92b0ae20b1ff6c3347a72e5fd4

Cracking Double MD5 — md5(md5($pass)) with hashcat

Save the hash to a file and run hashcat in mode -m 2600. Start with a wordlist such as rockyou.txt:

echo 'a936af92b0ae20b1ff6c3347a72e5fd4' > hash.txt && hashcat -m 2600 hash.txt /usr/share/wordlists/rockyou.txt

Add a rule set to mutate dictionary words (capitalisation, leetspeak, appended digits) and dramatically widen coverage:

echo 'a936af92b0ae20b1ff6c3347a72e5fd4' > hash.txt && hashcat -m 2600 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule