Since rules extracted with rulest can be used directly in tools like hashcat, after generating a substantial number of them I decided to briefly document the process of building highly optimal hashcat rules from that data in this short guide.
From 12 runs of the tool I obtained 12 rule files covering depths 1–10 (up to 10 operator+argument pairs per rule line).
$ tree . ├── found_chains.phase0.txt ├── found_chains.txt ├── rulest_output.phase0.txt ├── rulest_output.txt ├── rulest_raw.rule ├── rulest_rules_ga.rule ├── rulest_rules_no_ga.rule ├── rulest_rules_skull.rule ├── rulest_rules_strip_1p7m.rule ├── rulest_rules_strip_500k.rule ├── rulest_rules_strips.phase0.txt └── rulest_strip_hashmob.rule 0 directories, 12 files
After sorting by occurrence (frequency) I ended up with a file containing 4,384,527 unique rules. Not all of them are necessarily effective, so to find the most valuable ones I used the tried-and-true method of debugging rules against a large set of 32-hex hashes. The original plan was to use 160 million hashes, but an SSH connection drop mid-session made it impossible to repeat the full process — the debug run was ultimately completed against approximately ~70 million hashes, which still provides a solid statistical basis for frequency analysis.
$ cat * | uniq -c | sort -nr | cut -c 9- | awk '!seen[$0]++' > rulest2debug.rule $ wc -l rulest2debug.rule 4384527 rulest2debug.rule
I used the following script to run the debug pass:
→ https://github.com/A113L/bucket — run_debug.sh
--debug-mode=1 and --debug-file=rulest_debug_data.txt.
$ hashcat -a 0 -m 0 MD5_debug_hashes.txt wordlist.txt \ -r rulest2debug.rule \ --debug-mode=1 \ --debug-file=rulest_debug_data.txt
The resulting debug file was then processed through concentrator, which includes a Pareto-curve analysis mode designed for large sets of repeating debug data. Rules that appear most frequently across the debug output are the most valuable — that is the core principle behind the selection.
To use concentrator on the extracted rule set, simply run it without any arguments — this launches the program in interactive mode. The script begins by counting the total number of rules, so you know upfront how many you are working with.
$ ./concentrator Input Configuration: Enter rule files/directories (space-separated): rulest_debug_data.txt Analysing Input Data... ✅ SUCCESS: Rule file: rulest_debug_data.txt Quick Analysis: Files: 1 Sampled rules: 24,299,147 Est. total: 24,299,147 Unique sample: 1,048,061 Max rule len: 39 Recommendation: Low uniqueness → Extraction Long rules detected → consider functional minimization later. Processing Mode: 1 – Extract top existing rules 2 – Generate combinatorial rules 3 – Generate Markov rules Recommended: Mode 1 Select mode (1-3): 1 Top rules to extract [10000]: 24299147 Use statistical sort? [y/N]: n Global Settings: Output base name ['concentrator_output']: Max rule length to process [31]: Enable GPU acceleration? [Y/n]: y Process entirely in RAM? [y/N]: n Output Format: 1 – Standard line 2 – Expanded (space-separated operators) Select (1-2): 2 Temp directory [system default]: . Configuration Summary: Mode: extraction Input paths: 1 location(s) Output base: concentrator_output Max rule len: 31 GPU: Enabled In-memory: No Output format: expanded Top rules: 24,299,147 Stat sort: No Start processing? [Y/n]: y Active Mode: EXTRACTION Output File: concentrator_output_extracted.rule Output Format: expanded ✅ SUCCESS: OpenCL initialised on: NVIDIA GeForce RTX 3060 Ti ✅ SUCCESS: GPU Acceleration: ENABLED Collecting Rule Files (recursive, max depth 3) ✅ SUCCESS: Rule file: rulest_debug_data.txt ✅ SUCCESS: Found 1 rule files. ℹ️ INFO: Using temporary directory: . Parallel Rule File Analysis ℹ️ INFO: Parallel analysis of 1 files using 1 processes... Enter enhanced interactive mode? (Y/n): y ================================================================================ ENHANCED RULE PROCESSING – INTERACTIVE MENU ================================================================================ Initial dataset: 887,270 unique rules -------------------------------------------------------------------------------- ADVANCED FILTERING OPTIONS: (1) Filter by MINIMUM OCCURRENCE (2) Filter by MAXIMUM NUMBER OF RULES (top N) (3) Filter by FUNCTIONAL REDUNDANCY [RAM intensive] (4) INVERSE MODE – keep rules BELOW the cut-off rank (5) HASHCAT CLEANUP – validate (CPU/GPU modes) (6) LEVENSHTEIN FILTER – remove similar rules (7) TOGGLE OUTPUT FORMAT (currently: expanded) ANALYSIS & UTILITIES: (p) PARETO analysis (s) SAVE current rules (r) RESET to original dataset (i) Dataset information (q) QUIT -------------------------------------------------------------------------------- Enter choice: p
Once sorting is complete you will be dropped into a submenu where you can find the Pareto curve analysis along with milestone breakpoints showing exactly how many rules are needed to cover a given percentage of the entire initial dataset.
Pareto milestones from concentrator — rules needed to reach each coverage percentage of the full 887K-rule corpus (21.4M total occurrences).
| 10% coverage | 42 rules (0.0%) | |
| 20% coverage | 200 rules (0.0%) | |
| 30% coverage | 574 rules (0.1%) | |
| 40% coverage | 1,447 rules (0.2%) | |
| 50% coverage | 3,678 rules (0.4%) | |
| 60% coverage | 8,803 rules (1.0%) | |
| 70% coverage | 21,505 rules (2.4%) | |
| 80% coverage | 48,834 rules (5.5%) | |
| 90% coverage | 138,936 rules (15.7%) | |
| 95% coverage | 283,945 rules (32.0%) | |
| 99% coverage | 672,981 rules (75.8%) |
This makes it straightforward to cut the ruleset down to a practical size — for most cracking jobs the top 1–5% of rules by frequency covers the vast majority of real-world hits.
Using the Pareto milestones as cut points, four rule files were produced — one for each practical use case, from a large comprehensive set down to a tiny high-precision set:
$ wc -l *.rule 500001 rulest_large.rule 150001 rulest_medium.rule 25001 rulest_small.rule 251 rulest_tiny.rule 675254 total
Results from the
rules comparison spreadsheet.
Each of the four output files is compared against the best-in-class rule set in its weight
category, and against other existing rulest_* variants.
The existing rulest_* family in the benchmark includes
rulest_rules_strip_1p7m (44.65%, 1.7M rules),
rulest_rules_strip_1p1m (43.98%, 1.1M rules),
rulest_rules_strip (38.10%, 332k rules),
rulest_rules_ga (31.76%, 643k rules), and
rulest_rules_no_ga (31.35%, 329k rules).
The new rulest_large at 500k sits right in the middle of that family —
better recovery than the strip and GA variants while being a fraction of the size of
the 1M+ strip files. A good trade-off for most use cases.
The benchmark leaderboard has expanded significantly. New top entries include
Fordyv4a (56.94%, 4M rules), Fordyv4b (56.28%, 6.9M rules),
A11313M (53.97%, 3.2M rules), sapphire_v1 (52.06%, 1.27M rules),
and CakeV1 (52.04%, 1M rules). These large rule sets push the ceiling
considerably above the previous 48–49% range. The rulest_* output files
remain competitive within their respective size categories, but the top of the overall
leaderboard is now materially higher.
One thing worth highlighting: rulest runs comfortably on cards with less than 4 GB of VRAM. The entire ruleflow — rule generation, debug pass, concentrator analysis — can be run on modest hardware most people already own. You don't need a flagship GPU to produce a competitive rule set. The debug pass itself is the most time-consuming part, but even that is a one-time cost. The resulting files can then be reused across any number of jobs at no additional overhead.
Combined with the Pareto insight that a few thousand high-frequency rules cover a disproportionate share of real-world hashes, this means the barrier to having solid, personalized rule sets is much lower than it appears.
After a short break — and fixing a few bugs in rulest related
to generation and validation — I decided to run a quick second round (tagged r1) using the
rules already acquired, this time debugging against the hashmob.tiny.found dictionary
(~2 MB) rather than a full-size corpus. The rule pool itself was also refined and capped at
depth 1–8 instead of the previous 1–10.
Trimming the maximum chain length is a deliberate compromise, not a step back. Longer rules are disproportionately expensive to debug and score worse against a large hash database once the operator count climbs, so they yield fewer matches per unit of debug time. Capping at 8 keeps the rule space dense where it's actually worthwhile — this was somewhat confirmed by getting 6.75M rules out of seven rulest runs using comparatively small input files. That first approach was roughly hashmob.mini vs. rockyou in scale. For comparison, rulest on hashmob.micro vs. hashmob.small alone extracts 3.2M+ deduplicated rules in balanced RCR mode at the default depth of 6 — plenty to justify a debug pass as a first filtering step.
$ wc -l rulest2debug_r1.rule 6748072 rulest2debug_r1.rule $ ls -lh hashmob.tiny.found -rw-r--r-- 1 user user 2.0M hashmob.tiny.found
Output of the concentrator Pareto pass on the r1 debug run — 1,256,836 unique rules with 35,020,748 total occurrences. Unsurprisingly, the top ten are all classic insecure number-append patterns.
| #1 | $1$2 | 26,852 (0.1%) |
| #2 | $1$1 | 26,130 (0.2%) |
| #3 | $0$1 | 25,720 (0.2%) |
| #4 | $6$9 | 25,340 (0.3%) |
| #5 | $2$2 | 25,147 (0.4%) |
| #6 | $1$2$3 | 24,528 (0.4%) |
| #7 | $1$3 | 24,265 (0.5%) |
| #8 | $8$8 | 23,539 (0.6%) |
| #9 | $0$9 | 22,908 (0.6%) |
| #10 | $1320sz@E | 22,825 (0.7%) |
| 10% coverage | 579 rules (0.0%) | |
| 20% coverage | 3,992 rules (0.3%) | |
| 30% coverage | 12,052 rules (1.0%) | |
| 40% coverage | 25,549 rules (2.0%) | |
| 50% coverage | 45,184 rules (3.6%) | |
| 60% coverage | 73,167 rules (5.8%) | |
| 70% coverage | 113,287 rules (9.0%) | |
| 80% coverage | 178,368 rules (14.2%) | |
| 90% coverage | 328,294 rules (26.1%) | |
| 95% coverage | 513,640 rules (40.9%) | |
| 99% coverage | 919,200 rules (73.1%) |
Same shape as before, just a bigger pool underneath: 579 rules already reach 10% of total occurrences, and half the value sits in under 46k rules out of 1.26M total — even denser at the head than the previous r0 pass.
The four r1 rule files are cut straight off the milestone breakpoints above —
large ≈ 95%, medium ≈ 80%, small ≈ 40%, tiny ≈ 10% of cumulative coverage.
$ wc -l *_r1.rule 513641 rulest_large_r1.rule 179166 rulest_medium_r1.rule 25730 rulest_small_r1.rule 585 rulest_tiny_r1.rule 719122 total
Real numbers from the rules comparison spreadsheet, run against all four r1 rule files.
For the second respin (tagged r2) I pushed the rule depth even lower, capping at
depth 1–6 instead of the previous 1–8. The goal was to test whether a tighter,
denser rule space — extracted and debugged against a substantially larger corpus — could match
or exceed the r1 results while keeping the rule pool smaller and more focused.
The extraction phase used hashmob.mini.found as the base wordlist, extracted against hashmob.medium.found, SkullSecurityComp, and a small supplementary dictionary as targets. The resulting rule pool was then debugged against hashmob.small.found (2,341,652 words) run over 160,268,160 MD5 hashes. Corpus extraction took roughly 70 minutes, and the full debug pass across 2,103,114 rules completed in 4 hours and 40 minutes on the same RTX 3060 Ti.
Dropping from depth 8 to depth 6 is a significant constraint — it eliminates a large swath of multi-operator chains that rarely hit in practice but consume disproportionate debug time. If the coverage curve stays steep, it confirms that the highest-value rules are concentrated in short, predictable transforms rather than exotic long chains.
This respin also carries an update to rulest's Stage 3 (GA) —
the genetic algorithm's fitness function was changed from a raw hit-count to a
marginal coverage gain (submodular greedy) model. Individuals in each generation
are now sorted by raw hits and each is credited only for the base words it covers that no
higher-priority individual in that generation already covered — a chain that just duplicates
coverage another individual already provides scores ~0 fitness regardless of its own hit count.
This should push the GA toward genuinely complementary rule chains instead of rewarding
near-duplicates of already-strong rules.
$ wc -l rulest2debug_r2.rule 2103114 rulest2debug_r2.rule $ wc -l hashmob.small.found 2341652 hashmob.small.found $ wc -l MD5_debug_hashes_r2.txt 160268160 MD5_debug_hashes_r2.txt
Output of the concentrator Pareto pass on the r2 debug run, run after functional
minimization — 809,828 unique rules with 38,091,962 total occurrences.
The top rule alone (zZx38) already accounts for 0.5% of all
occurrences on its own, and the top 10 rules together cover 2.4% — a much
flatter drop-off than r1's top 10, dominated here by o0-append variants and
r^N^7^4^1-style reverse/truncate chains rather than single-operator rules.
| #1 | zZx38 | 205,065 (0.5%) |
| #2 | x93x91o0g | 128,833 (0.9%) |
| #3 | r^3^7^4^1so0 | 97,779 (1.1%) |
| #4 | r^4^7^4^1so0 | 88,903 (1.4%) |
| #5 | r^6^7^4^1so0 | 73,850 (1.6%) |
| #6 | r^7^8^4^1so0 | 66,637 (1.7%) |
| #7 | r^6^8^4^1so0 | 62,211 (1.9%) |
| #8 | x93sY5i93 | 61,727 (2.1%) |
| #9 | rst7^7^4^1$7 | 60,597 (2.2%) |
| #10 | ss5^2^7^4^1 | 60,121 (2.4%) |
| 10% coverage | 95 rules (0.0%) | |
| 20% coverage | 634 rules (0.1%) | |
| 30% coverage | 2,606 rules (0.3%) | |
| 40% coverage | 7,622 rules (0.9%) | |
| 50% coverage | 15,978 rules (2.0%) | |
| 60% coverage | 29,494 rules (3.6%) | |
| 70% coverage | 51,241 rules (6.3%) | |
| 80% coverage | 91,415 rules (11.3%) | |
| 90% coverage | 180,807 rules (22.3%) | |
| 95% coverage | 283,156 rules (35.0%) | |
| 99% coverage | 531,168 rules (65.6%) |
The r2 curve is noticeably flatter than r1's — hitting 90% of cumulative value now takes 180,807 rules (22.3% of the pool) versus a much smaller slice in r1, and 50% coverage alone already needs 15,978 rules. With depth capped at 6, value is spread across far more individually-weaker chains instead of concentrating in a small set of dominant short rules, which is the opposite of what the tighter depth cap was expected to produce.
The four r2 rule files are cut straight off the milestone breakpoints above —
but this round the actual cut points landed at large ≈ 99%, medium ≈ 90%, small ≈ 60%,
tiny ≈ 10% of cumulative coverage (versus large ≈ 95%/medium ≈ 80%/small ≈ 40%/tiny ≈ 10%
in r1), a direct consequence of the flatter r2 coverage curve above — hitting the same
relative tier required reaching further out into the pool. Each file carries 5 lines of
header comments.
$ wc -l *_r2.rule 531174 rulest_large_r2.rule 180813 rulest_medium_r2.rule 29500 rulest_small_r2.rule 101 rulest_tiny_r2.rule 741588 total
Real numbers from the rules comparison spreadsheet, run against all four r2 rule files, benchmarked as usual against a hashlist of 111,449 MD5 hashes using the hashmob.medium.found dictionary.
A short clip from the debug session, left here as a curiosity — just a few seconds of the hashcat debug pass itself.
Runtime: a few seconds, debug pass only