How to identify and crack an Android Backup hash

Android Backup is an archive encryption hash type. It uses a deliberately slow, salted key-derivation scheme, so only weak or short passwords are realistically recoverable. 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 Android Backup entirely in your browser — your hash is never uploaded. A typical example looks like this:

$ab$5*0*10000*b8900e4e...*7d6f...*...

Cracking Android Backup with hashcat

Save the hash to a file and run hashcat in mode -m 18900. Expect this to be slow — use a focused wordlist. Start with a wordlist such as rockyou.txt:

echo '$ab$5*0*10000*b8900e4e...*7d6f...*...' > hash.txt && hashcat -m 18900 hash.txt /usr/share/wordlists/rockyou.txt

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

echo '$ab$5*0*10000*b8900e4e...*7d6f...*...' > hash.txt && hashcat -m 18900 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Cracking Android Backup with John the Ripper

John the Ripper can attack the same hash with the androidbackup format:

echo '$ab$5*0*10000*b8900e4e...*7d6f...*...' > hash.txt && john --format=androidbackup --wordlist=/usr/share/wordlists/rockyou.txt hash.txt