Cracking in the Cloud with CUDA GPUs
Due to increasing popularity of
cloud-based instances for password cracking, we decided to focus our
efforts into streamlining Kali’s approach. We’ve noticed that Amazon’s
AWS P2-Series and Microsoft’s Azure NC-Series
are focused on Windows and Ubuntu. The corresponding blog posts and
guides followed suit. Although these instances are limited by the NVIDIA
Tesla K80’s hardware capabilities, the ability to quickly deploy a Kali
instance with CUDA support is appealing.
Installing proprietary graphics drivers
has always been a source of frustration; fortunately, improvements in
packaging have made this process much more seamless. Although we’ve done
the work for you in the cloud offerings, we’d like to help simplify
installation for your own use.
Prerequisites
First, you’ll need to ensure that your system is fully upgraded and that your card supports CUDA.
Note: GPUs with a CUDA compute capability > 5.0 are recommended, but GPUs with less will still work.
Note: GPUs with a CUDA compute capability > 5.0 are recommended, but GPUs with less will still work.
apt-get update && apt-get dist-upgrade -y
Once we’ve updated the system, we need to check for the nouveau kernel modules, and if enabled, blacklist them.
root@kali:~# lsmod |grep -i nouveau
nouveau 1499136 1
mxm_wmi 16384 1 nouveau
wmi 16384 2 mxm_wmi,nouveau
video 40960 1 nouveau
nouveau 1499136 1
mxm_wmi 16384 1 nouveau
wmi 16384 2 mxm_wmi,nouveau
video 40960 1 nouveau
echo -e "blacklist nouveau\noptions nouveau modeset=0\nalias nouveau off" > /etc/modprobe.d/blacklist-nouveau.conf
update-initramfs -u && reboot
Installation on a Local Computer
Once we have rebooted and have determined that the nouveau modules have not loaded, we will proceed to install the OpenCL ICD Loader, Drivers, and the CUDA toolkit.
apt-get install -y ocl-icd-libopencl1 nvidia-driver nvidia-cuda-toolkit
Verify Driver Installation
Now that our system should be ready to go, we need to verify the drivers have been loaded correctly. We can quickly verify this by running the nvidia-smi tool.
root@kali:~# nvidia-smi
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 375.26 Driver Version: 375.26 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 Tesla K80 Off | 0000:00:1E.0 Off | 0 |
| N/A 28C P0 53W / 149W | 0MiB / 11439MiB | 65% Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 375.26 Driver Version: 375.26 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 Tesla K80 Off | 0000:00:1E.0 Off | 0 |
| N/A 28C P0 53W / 149W | 0MiB / 11439MiB | 65% Default |
+-------------------------------+----------------------+----------------------+
With the output displaying our driver
and GPU correctly, we can now dive into password cracking. Before we get
too far ahead, let’s double check to make sure hashcat and CUDA are
working together.
root@kali:~# hashcat -I
OpenCL Info:
Platform ID #1
Vendor : NVIDIA Corporation
Name : NVIDIA CUDA
Version : OpenCL 1.2 CUDA 8.0.0
Device ID #1
Type : GPU
Vendor ID : 32
Vendor : NVIDIA Corporation
Name : Tesla K80
Version : OpenCL 1.2 CUDA
Processor(s) : 13
Clock : 823
Memory : 2047/11439 MB allocatable
OpenCL Version : OpenCL C 1.2
Driver Version : 375.26
OpenCL Info:
Platform ID #1
Vendor : NVIDIA Corporation
Name : NVIDIA CUDA
Version : OpenCL 1.2 CUDA 8.0.0
Device ID #1
Type : GPU
Vendor ID : 32
Vendor : NVIDIA Corporation
Name : Tesla K80
Version : OpenCL 1.2 CUDA
Processor(s) : 13
Clock : 823
Memory : 2047/11439 MB allocatable
OpenCL Version : OpenCL C 1.2
Driver Version : 375.26
If you receive the error clGetDeviceIDs(): CL_DEVICE_NOT_FOUND with Platform ID labeled Vendor: Mesa run:
apt-get remove mesa-opencl-icd
Benchmarking
root@kali:~# hashcat -b
OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: Tesla K80, 2047/11439 MB allocatable, 13MCU
Hashtype: MD5
Speed.Dev.#1.....: 4247.2 MH/s (102.66ms)
Hashtype: SHA1
Speed.Dev.#1.....: 1850.5 MH/s (58.64ms)
Hashtype: SHA256
Speed.Dev.#1.....: 785.1 MH/s (69.41ms)
OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: Tesla K80, 2047/11439 MB allocatable, 13MCU
Hashtype: MD5
Speed.Dev.#1.....: 4247.2 MH/s (102.66ms)
Hashtype: SHA1
Speed.Dev.#1.....: 1850.5 MH/s (58.64ms)
Hashtype: SHA256
Speed.Dev.#1.....: 785.1 MH/s (69.41ms)
Cracking
Now let’s crack some hashes. We are going to use the example NetNTLMv2 hash found on the hashcat wiki.
root@kali:~# hashcat -a 0 -m 5600 ntlmv2.hash dict.txt
OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: Tesla K80, 2047/11439 MB allocatable, 13MCU
ADMIN::N46iSNekpT:08ca45b7d7ea58ee:88dcbe4446168966a153a0064958dac6:5c7830315c7830310000000000000b45c67103d07d7b95acd12ffa11230e0000000052920b85f78d013c31cdb3b92f5d765c783030:hashcat
Session..........: hashcat
Status...........: Cracked
Hash.Type........: NetNTLMv2
Hash.Target......: ADMIN::N46iSNekpT:08ca45b7d7ea58ee:88dcbe4446168966a153a0064958dac6:5c7830315c7830310000000000000b45c67103d07d7b95acd12ffa11230e0000000052920b85f78d013c31cdb3b92f5d765c783030
Input.Base.......: File (dict.txt)
Input.Queue......: 1/1 (100.00%)
Speed.Dev.#1.....: 0 H/s (0.10ms)
Recovered........: 1/1 (100.00%) Digests, 1/1 (100.00%) Salts
Progress.........: 101/101 (100.00%)
OpenCL Platform #1: NVIDIA Corporation
======================================
* Device #1: Tesla K80, 2047/11439 MB allocatable, 13MCU
ADMIN::N46iSNekpT:08ca45b7d7ea58ee:88dcbe4446168966a153a0064958dac6:5c7830315c7830310000000000000b45c67103d07d7b95acd12ffa11230e0000000052920b85f78d013c31cdb3b92f5d765c783030:hashcat
Session..........: hashcat
Status...........: Cracked
Hash.Type........: NetNTLMv2
Hash.Target......: ADMIN::N46iSNekpT:08ca45b7d7ea58ee:88dcbe4446168966a153a0064958dac6:5c7830315c7830310000000000000b45c67103d07d7b95acd12ffa11230e0000000052920b85f78d013c31cdb3b92f5d765c783030
Input.Base.......: File (dict.txt)
Input.Queue......: 1/1 (100.00%)
Speed.Dev.#1.....: 0 H/s (0.10ms)
Recovered........: 1/1 (100.00%) Digests, 1/1 (100.00%) Salts
Progress.........: 101/101 (100.00%)
Success! We’ve cracked
the example hash and proven our installation is functional. There are a
multitude of configurations to improve cracking speed, not mentioned in
this guide. However, we encourage you to take a look at the hashcat documentation for your specific cases.
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