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.
git clone --depth 1 https://github.com/briiirussell/cybersecurity-skillsWrote 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/rules/briiirussell/cybersecurity-skills/breach-patterns)<a href="https://agentmods.dev/rules/briiirussell/cybersecurity-skills/breach-patterns"><img src="https://agentmods.dev/badge/rules/briiirussell/cybersecurity-skills/breach-patterns.svg" alt="Measured on agentmods" 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 | $0.00149 | $0.03075 |
| Opus 5 | $0.00075 | $0.01537 |
| Sonnet 5 | $0.00030 | $0.00615 |
| Haiku 4.5 | $0.00015 | $0.00308 |
Grade B, and why
breach-patterns scanned grade B 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 8d 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.
Cloud metadata endpointmediumServer-side request forgery
One request to 169.254.169.254 can return temporary IAM credentials.
- SSRF defences on every URL-taking endpoint — see `owasp-audit` A10 bypass matrix (especially the cloud metadata endpoints row: `169.254.169.254`, `metadata.google.internal`, `169.254.170.2`) Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 227 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Breach Patterns — Preemptive Hardening from Public Breach Disclosures
The inverse of incident-triage. That skill is "we're on fire, what now." This skill is "go read the breach writeups, extract the audit question each one implies, and check your own stack."
Breaches catalogued here are public, well-documented, and pattern-bearing. Each pattern surfaces a control or check that often falls between OWASP categories — IMDS abuse, supplier credential blast radius, secrets-in-CI, single-sign-on lateral movement, log-tampering pre-breach. These are the controls people add after their first incident; reading other people's breaches is cheaper than writing your own.
Cross-references: every audit skill in this repo. Use this skill to surface "have we considered X?" questions, then pivot to the relevant audit skill for the deep dive. When a breach pattern surfaces a regulatory implication — health data exposure, payment card data exposure, PII exposure — also reach for hipaa-audit, pci-audit, or privacy-engineering to understand the regulatory clock and notification obligations that come with that breach class.
How to use this skill
For each breach pattern below:
- Read the one-paragraph summary of the breach
- Ask the audit question(s) it implies for your environment
- Map to specific checks in the existing audit skills
- Decide disposition — "we've confirmed this can't happen," "we have a gap, here's the plan," or "we accept-risk for these reasons"
The output is a "breach-pattern coverage" document — not a fixed report, an evergreen checklist you re-run against your evolving stack.
Pattern 1 — IMDS abuse (Capital One, 2019)
What happened: A misconfigured WAF allowed SSRF. An attacker used SSRF to reach the EC2 instance metadata service (IMDSv1, no token requirement), pulled temporary IAM credentials, and used them to enumerate and exfiltrate S3 buckets containing 100M+ records.
Audit question: Does any service that takes a URL from user input also have IAM credentials reachable via IMDS?
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.
- 8d ago First seen · 227 lines · 149 tokens per session scan B eec880e0de04
breach-patterns is a cursor rule published in the GitHub repository briiirussell/cybersecurity-skills (383 stars, last pushed 3mo ago), licensed MIT. It adds 149 tokens to every session and 3,075 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it B with 1 finding (cloud metadata endpoint). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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