Excel Protected Workbook Known PW Length

[HelmanFrow]

Okay, remember how I reported that my last attack hung while initializing the GPU? That was over six hours ago.
I actually never terminated that attempt; I minimized the PowerShell window and switched to another desktop to finish some other work. I also uninstalled the CUDA Toolkit at some point during that time.

I just switched back to that desktop to find that the attack has been RUNNING for 33 minutes.

I kid you not:

Code:

PS D:\desktop\hashcat-6.2.5> ./hashcat.exe -d 2 -m9600 -a 3 --username -1 ?l?u hash.txt ?1?1?1?1
hashcat (v6.2.5) starting

nvmlDeviceGetFanSpeed(): Not Supported

nvmlDeviceGetTemperatureThreshold(): Not Supported

CUDA API (CUDA 11.4)
====================
* Device #1: Quadro M1000M, skipped

OpenCL API (OpenCL 3.0 CUDA 11.4.156) - Platform #1 [NVIDIA Corporation]
========================================================================
* Device #2: Quadro M1000M, 1728/2048 MB (512 MB allocatable), 4MCU

OpenCL API (OpenCL 3.0 ) - Platform #2 [Intel(R) Corporation]
=============================================================
* Device #3: Intel(R) HD Graphics 530, skipped

Minimum password length supported by kernel: 0
Maximum password length supported by kernel: 256

Hashes: 1 digests; 1 unique digests, 1 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates

Optimizers applied:
* Zero-Byte
* Single-Hash
* Single-Salt
* Brute-Force
* Slow-Hash-SIMD-LOOP
* Uses-64-Bit

Watchdog: Temperature abort trigger set to 90c

Host memory required for this attack: 111 MB

Cracking performance lower than expected?

* Append -w 3 to the commandline.
  This can cause your screen to lag.

* Append -S to the commandline.
  This has a drastic speed impact but can be better for specific attacks.
  Typical scenarios are a small wordlist but a large ruleset.

* Update your backend API runtime / driver the right way:
  https://hashcat.net/faq/wrongdriver

* Create more work items to make use of your parallelization power:
  https://hashcat.net/faq/morework

Driver temperature threshold met on GPU #2. Expect reduced performance.
Driver temperature threshold met on GPU #2. Expect reduced performance.
Driver temperature threshold met on GPU #2. Expect reduced performance.

[s]tatus [p]ause [b]ypass [c]heckpoint [f]inish [q]uit =>

Session..........: hashcat
Status...........: Running
Hash.Mode........: 9600 (MS Office 2013)
Hash.Target......: $office$*2013*100000*256*16*be504576f33edb6cb25d640...76d274
Time.Started.....: Sun Mar 20 21:21:34 2022 (33 mins, 39 secs)
Time.Estimated...: Sun Mar 20 23:24:14 2022 (1 hour, 29 mins)
Kernel.Feature...: Pure Kernel
Guess.Mask.......: ?1?1?1?1 [4]
Guess.Charset....: -1 ?l?u, -2 Undefined, -3 Undefined, -4 Undefined
Guess.Queue......: 1/1 (100.00%)
Speed.#2.........:      995 H/s (10.15ms) @ Accel:128 Loops:64 Thr:128 Vec:1
Recovered........: 0/1 (0.00%) Digests
Progress.........: 1998848/7311616 (27.34%)
Rejected.........: 0/1998848 (0.00%)
Restore.Point....: 32768/140608 (23.30%)
Restore.Sub.#2...: Salt:0 Amplifier:18-19 Iteration:52992-53056
Candidate.Engine.: Device Generator
Candidates.#2....: wnny -> wypb
Hardware.Mon.#2..: Temp: 74c Util: 98% Core:1097MHz Mem:2505MHz Bus:16

[s]tatus [p]ause [b]ypass [c]heckpoint [f]inish [q]uit =>

I had to do a double-take but there it is! Did it actually take five-and-a-half hours to initialize the runtime or did something kick in when I uninstalled the CUDA Toolkit?

The funny thing is that I was just about to install a previous version of CUDA Toolkit which includes PTX 7.4 because the current version (which includes PTX 7.6) doesn't seem to be supported by HashCat in its current release.