PDF 1.4 Password hash cracking

[Sheldor]

Hi,
I lost a Password of a important PDF file.
At the moment I am trying to recover the Password with this Parameter:

cudaHashcat64.exe -m 10500 -a myHash.txt -a 3 ?b?b?b?b?b

I am not sure if the Parameter are so right.
The Password can be any characters  ans the password is 8-12 characters long.
My GPU is a GTX 970

Are the Parameter so fine?

Thank you

[Mem5]

cudaHashcat64.exe -m 10500 -a myHash.txt -a 3 ?b?b?b?b?b

- You have twice "-a"
- ?b 5 times means 5 characters

[Sheldor]

the "-a" is a copy&paste error. Sorry for that
When I have a Password with 12 characters so I use "cudaHashcat64.exe -m 10500 -a myHash.txt -a 3 ?b?b?b?b?b?b?b?b?b?b?b?b"??

But I get this "error":
ATTENTION!
The wordlist or mask you are using is too small.
Therefore, oclHashcat is unable to utilize the full parallelization power of your GPU(s).
The cracking speed will drop.
Workaround: https://hashcat.net/wiki/doku.php?id=fre...full_speed


INFO: approaching final keyspace, workload adjusted

[Mem5]

https://hashcat.net/wiki/doku.php?id=fre...ese_hashes

--increment: enable incremental mode (see #1 above)
--increment-min 4: set the minimum length of the password candidates to 4 (in this case)
--increment-max 6: set the maximum length of the password candidates to 6 (in this case)

Builtin charset :
?a = ?l?u?d?s
?b = 0x00 - 0xff

You may not need ?b..

[rico]

Your command doesn't really matter. The GTX 970 benchmarks at about 7800 kH/s for this hash type so even just 8 character passwords including all characters is 95^8 combinations. It will take almost 30 years to try all 8 char combinations on the 970.

9 chars will take two and a half millennia...

Maybe a nice dictionary attack might be better (unless passwords are randomly generated).

[epixoip]

The reason why you are getting "mask too small" is because of integer overflow. 255^12 > 2^63.

[Sheldor]

Thanks for the answers.
Now I am trying to get the PW whit a word list
The comant is:

cudaHashcat64.exe cudaHashcat64.exe -m 10500 -a 0 -o GotIT.txt myhash.txt final-wordlist.txt

but I get this Error:

...
WARNING: Hashfile 'cudaHashcat64.exe' in line 1043 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1044 (20`pP└
): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1045 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1046 (
&): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1047 (p   └ðÓ­): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1048 (p   └ðÓ­): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1049 (0   pP└ðÓ
): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1050 (0   p└ðÓ
P): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1051 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1052 (20`pP└
): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1053 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1054 (p   └ðÓ­

): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1055 (p   └ðÓ­): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1056 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1057 (p   └ðÓ­
): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1058 (0   pP└ð): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1059 (p   └ðÓ­): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1060 (0   pP└ðÓ
): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1061 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1062 (): Line-length exception
WARNING: Hashfile 'cudaHashcat64.exe' in line 1063 (E): Line-length exception
Parsed Hashes: 1063/1063 (100.00%)

ERROR: No hashes loaded

[rico]

You have only one GTX 970, not two, so only run one cudaHashcat64.exe, not two.

Change this:
cudaHashcat64.exe cudaHashcat64.exe -m 10500 -a 0 -o GotIT.txt myhash.txt final-wordlist.txt

To this:

cudaHashcat64.exe -m 10500 -a 0 -o GotIT.txt myhash.txt final-wordlist.txt