04-07-2025, 11:30 PM
Hi.
I have problem on Hybrid attack mode (-a 6). When i try to crack an md5crypt hash with -a 6, Hashcat can't crack the password using only GPU. But if i force to use only CPU (-D 1) with the same attack mode, it cracks the password without any problem.
The command i use:
hashcat hash.txt -m 500 -a 6 word.txt ?d?d
hash.txt content:
root:$1$XX$.XXXXXXXXXXXXXXXXg1KQ0:0:0:root:/root/:/bin/psh
word.txt content:
testpsw
XXXXXXXXXXpav
The correct password is XXXXXXXXXXpav33, but hashcat can't crack it using only GPU. I also tried replacing the lines. It tries the correct password, but can't crack it:
If i force to use only CPU, it cracks without any problem:
Another interesting thing is, when i add any character to the testpsw (for example testtpsw), it cracks the password on GPU too. So when there is another line in the word.txt file which is 7 characters long, it fails to crack. When its length lower than 7 or higher than 7, it cracks the password on GPU too.
Hashcat version info
I tried the same attack mode with the same files (which fails to crack on Hashcat) on John the Ripper using only GPU (format=md5crypt-opencl), it cracks without any problem.
I have problem on Hybrid attack mode (-a 6). When i try to crack an md5crypt hash with -a 6, Hashcat can't crack the password using only GPU. But if i force to use only CPU (-D 1) with the same attack mode, it cracks the password without any problem.
The command i use:
hashcat hash.txt -m 500 -a 6 word.txt ?d?d
hash.txt content:
root:$1$XX$.XXXXXXXXXXXXXXXXg1KQ0:0:0:root:/root/:/bin/psh
word.txt content:
testpsw
XXXXXXXXXXpav
The correct password is XXXXXXXXXXpav33, but hashcat can't crack it using only GPU. I also tried replacing the lines. It tries the correct password, but can't crack it:
Code:
Candidate.Engine.: Device Generator
Candidates.#1....: testpsw33 -> XXXXXXXXXXpav33If i force to use only CPU, it cracks without any problem:
Code:
hashcat hash.txt -m 500 -a 6 word.txt ?d?d -D 1
$1$XX$.XXXXXXXXXXXXXXXXg1KQ0:XXXXXXXXXXpav33Another interesting thing is, when i add any character to the testpsw (for example testtpsw), it cracks the password on GPU too. So when there is another line in the word.txt file which is 7 characters long, it fails to crack. When its length lower than 7 or higher than 7, it cracks the password on GPU too.
Hashcat version info
Code:
hashcat -I
hashcat (v6.2.6) starting in backend information mode
OpenCL Info:
============
OpenCL Platform ID #1
Vendor..: Intel(R) Corporation
Name....: Intel(R) OpenCL HD Graphics
Version.: OpenCL 3.0
Backend Device ID #1
Type...........: GPU
Vendor.ID......: 8
Vendor.........: Intel(R) Corporation
Name...........: Intel(R) UHD Graphics
Version........: OpenCL 3.0 NEO
Processor(s)...: 80
Clock..........: 1300
Memory.Total...: 3146 MB (limited to 786 MB allocatable in one block)
Memory.Free....: 1536 MB
Local.Memory...: 64 KB
OpenCL.Version.: OpenCL C 1.2
Driver.Version.: 31.0.101.3959
OpenCL Platform ID #2
Vendor..: Intel(R) Corporation
Name....: Intel(R) OpenCL
Version.: OpenCL 3.0 WINDOWS
Backend Device ID #2
Type...........: CPU
Vendor.ID......: 8
Vendor.........: Intel(R) Corporation
Name...........: 12th Gen Intel(R) Core(TM) i5-1240P
Version........: OpenCL 3.0 (Build 0)
Processor(s)...: 16
Clock..........: 0
Memory.Total...: 7865 MB (limited to 1966 MB allocatable in one block)
Memory.Free....: 3900 MB
Local.Memory...: 256 KB
OpenCL.Version.: OpenCL C 3.0
Driver.Version.: 2025.19.3.0.17_230222I tried the same attack mode with the same files (which fails to crack on Hashcat) on John the Ripper using only GPU (format=md5crypt-opencl), it cracks without any problem.