claude-red is a library of structured skills that give Claude specialized offensive-security methods for areas such as web vulnerabilities, shellcode, exploit development, and identity systems. It is intended for authorized red-team work, bug-bounty triage, security research, CTF preparation, and operator training. Its catalogue contains the project's skills for loading these security specializations into Claude.
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 SnailSploit/Claude-Red --skill offensive-race-conditiongit clone --depth 1 https://github.com/SnailSploit/Claude-RedWrote 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/snailsploit/claude-red/offensive-race-condition)<a href="https://agentmods.dev/skills/snailsploit/claude-red/offensive-race-condition"><img src="https://agentmods.dev/badge/skills/snailsploit/claude-red/offensive-race-condition/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/snailsploit/claude-red/offensive-race-condition"><img src="https://agentmods.dev/badge/skills/snailsploit/claude-red/offensive-race-condition.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 5 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 165 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 203 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 165 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 203 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 402 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 | $0.00000 | $0.06337 |
| Opus 5.5 | $0.00000 | $0.02535 |
| Sonnet 5.5 | $0.00000 | $0.01267 |
| Haiku 4.5 | $0.00000 | $0.00634 |
Grade B, and why
offensive-race-condition scanned grade B with 2 findings 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.
Sends data to an external URLmediumData exfiltration
A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.
requests.post('https://target.com/api/redeem', Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
requests.post('https://target.com/api/redeem', How it starts
The opening of the file, as written. The whole thing — 880 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Race Conditions
Metadata
- Skill Name: race-condition
- Folder: offensive-race-condition
- Source: https://github.com/SnailSploit/offensive-checklist/blob/main/race-condition.md
Description
Race condition (TOCTOU) testing checklist: identifying timing windows, Burp Suite Turbo Intruder, Last-Byte sync technique, rate limit bypass, double-spend attacks, and concurrent request exploitation. Use for web app race condition testing or bug bounty time-of-check-to-time-of-use bugs.
Trigger Phrases
Use this skill when the conversation involves any of:
race condition, TOCTOU, timing attack, Turbo Intruder, last-byte sync, rate limit bypass, double spend, concurrent request, race window, time of check, time of use
Instructions for Claude
When this skill is active:
- Load and apply the full methodology below as your operational checklist
- Follow steps in order unless the user specifies otherwise
- For each technique, consider applicability to the current target/context
- Track which checklist items have been completed
- Suggest next steps based on findings
Full Methodology
Race Conditions
Shortcut
- Spot the features prone to race conditions in the target application and copy the corresponding requests.
- Send multiple of these critical requests to the server simultaneously. You should craft requests that should be allowed once but not allowed multiple times.
- Check the results to see if your attack has succeeded. And try to execute the attack multiple times to maximize the chance of success.
- Consider the impact of the race condition you just found.
Mechanisms
Race conditions occur when the behavior of a system depends on the relative timing or sequence of events that can happen in different orders. In web application security, race conditions happen when multiple concurrent processes or threads access and manipulate the same resource simultaneously without proper synchronization.
sequenceDiagram
participant Thread1 as Thread 1
participant Resource
participant Thread2 as Thread 2
Thread1->>Resource: Read value (100)
Thread2->>Resource: Read value (100)
Thread1->>Thread1: Calculate new value (100-10=90)
Thread2->>Thread2: Calculate new value (100-10=90)
Thread1->>Resource: Write new value (90)
Thread2->>Resource: Write new value (90)
Note over Resource: Expected final value: 80<br/>Actual final value: 90
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 · 880 lines · 0 tokens per session scan B 802e2f87e90c
offensive-race-condition is a skill published in the GitHub repository SnailSploit/Claude-Red (8,487 stars, last pushed 12d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 6,337 tokens. A static security scan graded it B with 2 findings (sends data to an external url, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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