Hashcat is a password recovery tool. It had a proprietary code base until 2015, but was then released as open source software. Versions are available for Linux, OS X, and Windows. Examples of hashcat-supported hashing algorithms are LM hashes, MD4, MD5, SHA-family and Unix Crypt formats as well as algorithms used in MySQL and Cisco PIX.
|Developer(s)||Jens 'atom' Steube, Gabriele 'matrix' Gristina|
6.1.1 / 29 July 2020
Hashcat has been publicly noticed because of its optimizations; partly based on flaws in other software discovered by the creator of hashcat. An example was a flaw in 1Password's password manager hashing scheme. It has also been compared to similar software in a Usenix publication and been described on Ars technica.
Previously, two variants of hashcat existed:
- hashcat - CPU-based password recovery tool
- oclHashcat/cudaHashcat - GPU-accelerated tool (OpenCL or CUDA)
Many of the algorithms supported by hashcat-legacy (such as MD5, SHA1, and others) can be cracked in a shorter time with the GPU-based hashcat. However, not all algorithms can be accelerated by GPUs. Bcrypt is an example of this. Due to factors such as data-dependent branching, serialization, and memory (and more), oclHashcat/cudaHashcat weren't catchall replacements for hashcat-legacy.
hashcat-legacy is available for Linux, OSX and Windows. hashcat is available for macOS, Windows, and Linux with GPU, CPU and generic OpenCL support which allows for FPGAs and other accelerator cards.
$ hashcat -d 2 -a 0 -m 400 -O -w 4 example400.hash example.dict hashcat (v5.1.0) starting... OpenCL Platform #1: Intel(R) Corporation ======================================== * Device #1: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz, skipped. OpenCL Platform #2: NVIDIA Corporation ====================================== * Device #2: GeForce GTX 970, 1010/4041 MB allocatable, 13MCU * Device #3: GeForce GTX 750 Ti, skipped. Hashes: 1 digests; 1 unique digests, 1 unique salts Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates Rules: 1 Applicable optimizers: * Optimized-Kernel * Zero-Byte * Single-Hash * Single-Salt Minimum password length supported by kernel: 0 Maximum password length supported by kernel: 55 Watchdog: Temperature abort trigger set to 90c Dictionary cache hit: * Filename..: example.dict * Passwords.: 128416 * Bytes.....: 1069601 * Keyspace..: 128416 The wordlist or mask that you are using is too small. This means that hashcat cannot use the full parallel power of your device(s). Unless you supply more work, your cracking speed will drop. For tips on supplying more work, see: https://hashcat.net/faq/morework Approaching final keyspace - workload adjusted. $H$9y5boZ2wsUlgl2tI6b5PrRoADzYfXD1:hash234 Session..........: hashcat Status...........: Cracked Hash.Type........: phpass, WordPress (MD5), phpBB3 (MD5), Joomla (MD5) Hash.Target......: $H$9y5boZ2wsUlgl2tI6b5PrRoADzYfXD1 Time.Started.....: Thu Apr 25 05:10:35 2019 (0 secs) Time.Estimated...: Thu Apr 25 05:10:35 2019 (0 secs) Guess.Base.......: File (example.dict) Guess.Queue......: 1/1 (100.00%) Speed.#2.........: 2654.9 kH/s (22.24ms) @ Accel:128 Loops:1024 Thr:1024 Vec:1 Recovered........: 1/1 (100.00%) Digests, 1/1 (100.00%) Salts Progress.........: 128416/128416 (100.00%) Rejected.........: 0/128416 (0.00%) Restore.Point....: 0/128416 (0.00%) Restore.Sub.#2...: Salt:0 Amplifier:0-1 Iteration:1024-2048 Candidates.#2....: 0 -> zzzzzzzzzzz Hardware.Mon.#2..: Temp: 44c Fan: 40% Util: 50% Core:1265MHz Mem:3004MHz Bus:8 Started: Thu Apr 25 05:10:32 2019 Stopped: Thu Apr 25 05:10:37 2019
Hashcat offers multiple attack modes for obtaining effective and complex coverage over a hash's keyspace. These modes are:
- Brute-force attack
- Combinator attack
- Dictionary attack
- Fingerprint attack
- Hybrid attack
- Mask attack
- Permutation attack
- Rule-based attack
- Table-Lookup attack (CPU only)
- Toggle-Case attack
- PRINCE attack (in CPU version 0.48 and higher only)
The traditional bruteforce attack is considered outdated, and the Hashcat core team recommends the Mask-Attack as a full replacement.
Team Hashcat (the official team of the Hashcat software composed of core Hashcat members) won first place in the KoreLogic "Crack Me If you Can" Competitions at DefCon in 2010, 2012, 2014, 2015, and 2018, and at DerbyCon in 2017.
- "On hashcat and strong Master Passwords as your best protection". Passwords. Agile Bits. 16 April 2013.
- Ur, Blase (12 August 2015). "Measuring Real-World Accuracies and Biases in Modeling Password Guessability" (PDF). Proceedings of the 24th USENIX Security Symposium.
- Goodin, Dan (26 August 2013). ""thereisnofatebutwhatwemake" - Turbo-charged cracking comes to long passwords". Ars Technica. Retrieved 21 July 2020.
- "hashcat v3.00". Hashcat. Hashcat project. 29 June 2016.
- "Recent Developments in Password Cracking". Passwords. Bruce Schneier. 19 September 2012.
- "PRINCE: modern password guessing algorithm" (PDF). Hashcat site. Hashcat. 8 December 2014.
- Team Hashcat
- ""Crack Me If You Can" - DEFCON 2010". contest-2010.korelogic.com. Retrieved 21 July 2020.
- "Crack Me If You Can 2014 Contest". KoreLogic Security.
- "Another trophy in the Pocket! Win @ CMIYC contest 2015". hashcat.net. Retrieved 21 July 2020.
- Official website
- A guide to password cracking with Hashcat
- Talk: Confessions of a crypto cluster operator based on oclHashcat at Derbycon 2015
- Talk: Hashcat state of the union at Derbycon 2016