Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add SecurityTalent/bugskill-ai --skill hash-attack-techniquesgit clone --depth 1 https://github.com/SecurityTalent/bugskill-aiWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/securitytalent/bugskill-ai/hash-attack-techniques)<a href="https://agentmods.dev/skills/securitytalent/bugskill-ai/hash-attack-techniques"><img src="https://agentmods.dev/badge/skills/securitytalent/bugskill-ai/hash-attack-techniques/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/securitytalent/bugskill-ai/hash-attack-techniques"><img src="https://agentmods.dev/badge/skills/securitytalent/bugskill-ai/hash-attack-techniques.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00046 | $0.03962 |
| Opus 5.5 | $0.00018 | $0.01585 |
| Sonnet 5.5 | $0.00009 | $0.00792 |
| Haiku 4.5 | $0.00005 | $0.00396 |
Grade A, and why
hash-attack-techniques scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
requests.get(url, params={**data, "mac": candidate}) This is a copy
100% identical to hash-attack-techniques — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 492 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Hash Attack Techniques — Expert Cryptanalysis Playbook
AI LOAD INSTRUCTION: Expert hash attack techniques for CTF and security assessments. Covers length extension attacks, MD5/SHA1 collision generation, meet-in-the-middle hash attacks, HMAC timing side channels, birthday attacks, and proof-of-work solving. Base models often incorrectly apply length extension to HMAC or SHA-3, or fail to distinguish between identical-prefix and chosen-prefix collisions.
0. RELATED ROUTING
- rsa-attack-techniques when hash weaknesses affect RSA signature schemes
- symmetric-cipher-attacks when hash is used in key derivation
- classical-cipher-analysis when analyzing hash-like constructions in classical ciphers
Quick attack selection
| Scenario | Attack | Tool |
|---|---|---|
H(secret || msg) known, extend message |
Length extension | HashPump, hash_extender |
| Need two files with same MD5 | Identical-prefix collision | fastcoll |
| Need specific MD5 prefix match | Chosen-prefix collision | hashclash |
| Byte-by-byte HMAC comparison | Timing attack | Custom script |
| Find any collision | Birthday attack | O(2^(n/2)) |
| Proof of work: find hash with leading zeros | Brute force | hashcat, Python |
1. LENGTH EXTENSION ATTACK
1.1 Vulnerable vs Non-Vulnerable
| Hash | Vulnerable | Why |
|---|---|---|
| MD5 | Yes | Merkle-Damgard construction |
| SHA-1 | Yes | Merkle-Damgard construction |
| SHA-256 | Yes | Merkle-Damgard construction |
| SHA-512 | Yes | Merkle-Damgard construction |
| SHA-3 / Keccak | No | Sponge construction |
| HMAC-* | No | Double hashing prevents extension |
| SHA-256 truncated | No (if truncated) | Missing internal state bits |
| BLAKE2 | No | Different construction |
1.2 Attack Mechanism
Given: MAC = H(secret || original_message)
Known: original_message, len(secret), MAC value
Compute: H(secret || original_message || padding || extension)
WITHOUT knowing the secret!
How: The MAC value IS the internal hash state after processing
(secret || original_message || padding).
Initialize hash with this state, continue hashing extension.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 492 lines · 46 tokens per session scan A 0a6177b6ab81
hash-attack-techniques is a skill published in the GitHub repository SecurityTalent/bugskill-ai (13 stars, last pushed 21d ago), licensed MIT. It adds 46 tokens to every session and 3,962 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to hash-attack-techniques, differing in 0 lines, and is treated as a copy.
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