How to identify and crack a PDF 1.7 Level 8 (Acrobat 10-11) hash

PDF 1.7 Level 8 (Acrobat 10-11) is a document 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 PDF 1.7 Level 8 (Acrobat 10-11) entirely in your browser — your hash is never uploaded. A typical example looks like this:

$pdf$5*6*256*-1028*1*16*...

Cracking PDF 1.7 Level 8 (Acrobat 10-11) with hashcat

Save the hash to a file and run hashcat in mode -m 10700. Expect this to be slow — use a focused wordlist. Start with a wordlist such as rockyou.txt:

echo '$pdf$5*6*256*-1028*1*16*...' > hash.txt && hashcat -m 10700 hash.txt /usr/share/wordlists/rockyou.txt

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

echo '$pdf$5*6*256*-1028*1*16*...' > hash.txt && hashcat -m 10700 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Cracking PDF 1.7 Level 8 (Acrobat 10-11) with John the Ripper

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

echo '$pdf$5*6*256*-1028*1*16*...' > hash.txt && john --format=pdf --wordlist=/usr/share/wordlists/rockyou.txt hash.txt