Insecure Deserialization Playbook
PentesterFlow/agent
Fingerprints which language or framework produced a serialized blob, then helps build a working gadget chain to test for insecure deserialization.
Insecure deserialization detection and gadget chain exploitation
Install Deserialization Testing
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testing --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .claude/skills && cp -r skills-src/agent/skills/deserialization-testing .claude/skills/deserialization-testing && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .claude/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testingType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testing --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .agents/skills && cp -r skills-src/agent/skills/deserialization-testing .agents/skills/deserialization-testing && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .agents/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testing --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/agent/skills/deserialization-testing .cursor/skills/deserialization-testing && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .cursor/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/NeoTheCapt/RedteamAgent.git --path agent/skills/deserialization-testing--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testing --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/agent/skills/deserialization-testing .gemini/skills/deserialization-testing && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .gemini/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testingInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .github/skills && cp -r skills-src/agent/skills/deserialization-testing .github/skills/deserialization-testing && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .github/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install NeoTheCapt/RedteamAgent deserialization-testing --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/NeoTheCapt/RedteamAgent.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/agent/skills/deserialization-testing .opencode/skills/deserialization-testing && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "deserialization-testing" agent skill from https://github.com/NeoTheCapt/RedteamAgent/tree/master/agent/skills/deserialization-testing into .opencode/skills/deserialization-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deserialization-testing", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
deserialization-testing- GitHub stars
- 140
- Token cost
- ~836 tokens
- SKILL.md length
- 355 words
- Files
- 1
- Skills in repo
- 25
- Repo updated
- First seen
- Licence
- None found
At a glance
Insecure deserialization detection and gadget chain exploitation
- Works in 7 steps: Identify Serialized Data → Java Deserialization → PHP Deserialization → …
- Tasks that involve Penetration testing
- SKILL.md covers When to Activate, Tools, Methodology and What to Record
- Calls java
What it does
Deserialization Testing is an agent skill from NeoTheCapt/RedteamAgent. Insecure deserialization detection and gadget chain exploitation
Its SKILL.md is about 840 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Security, covering Penetration testing. It works with Java, PHP, Python and .NET. The repository describes itself as: An AI red-team agent for authorized labs and web app pentesting workflows. Turns Claude Code / OpenCode / Codex into a structured recon → test → exploit → report workflow, with…
When your agent uses it
- Tasks that involve Penetration testing
Example prompts
- “/deserialization-testing”
Requirements
- Python 3
Workflow steps
7 steps, taken from the step headings in SKILL.md.
- Identify Serialized Data
- Java Deserialization
- PHP Deserialization
- Python Pickle
- .NET Deserialization
- Impact Validation
- Data Tampering (Non-RCE)
What it can do on your machine
Read from SKILL.md and the folder at commit 2e60476. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
java
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Deserialization Testing loads about 836 tokens when it runs. Until then it costs about 22 tokens; SKILL.md has 355 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Without a licence we can't republish the file, so here is its outline and opening line. It has 355 words (~836 tokens).
“java -jar ysoserial.jar CommonsCollections1 "id" | base64”
- name
- deserialization-testing
- origin
- RedteamOpencode
Files
Just SKILL.md in agent/skills/deserialization-testing of NeoTheCapt/RedteamAgent.
Open the folder on GitHubat commit 2e60476
Compare with similar skills
Deserialization Testing next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Deserialization Testing this skillNeoTheCapt/RedteamAgent | 140 | — | ~836 | Automated safety check: Pass | None | |
| Insecure Deserialization PlaybookPentesterFlow/agent | 1.4k | — | ~1.7k | Automated safety check: Pass | Apache-2.0 | |
| SstiPentesterFlow/agent | 1.4k | — | ~1.2k | Automated safety check: Pass | Apache-2.0 | |
| Hunt DeserializationEncod3d-Sec/TORCH | 329 | — | ~1.7k | Automated safety check: Pass | MIT | |
| Dt Obs ServicesDynatrace/dynatrace-for-ai | 161 | — | ~3.3k | Automated safety check: Pass | Apache-2.0 | |
| Assess Migrationmendixlabs/mxcli | 128 | — | ~3.6k | Automated safety check: Notes | Apache-2.0 |
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Related
Categories
Questions about Deserialization Testing
What does Deserialization Testing do?
Insecure deserialization detection and gadget chain exploitation. Deserialization Testing is an agent skill from NeoTheCapt/RedteamAgent.
When should I use Deserialization Testing?
Deserialization Testing fits situations like: tasks that involve Penetration testing.
How do I install Deserialization Testing in Claude Code?
Run `npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a claude-code`. Or copy the skill folder (agent/skills/deserialization-testing in NeoTheCapt/RedteamAgent) into .claude/skills/deserialization-testing in your project. Claude Code loads it when a task matches its description.
How do I install Deserialization Testing in Codex?
Run `npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a codex`. Or copy the skill folder (agent/skills/deserialization-testing in NeoTheCapt/RedteamAgent) into .agents/skills/deserialization-testing in your project. Codex loads it when a task matches its description.
Can I use Deserialization Testing in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add NeoTheCapt/RedteamAgent --skill deserialization-testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/deserialization-testing, .gemini/skills/deserialization-testing, .github/skills/deserialization-testing and .opencode/skills/deserialization-testing in your project.
What does Deserialization Testing need to run?
Going by SKILL.md and its folder, Deserialization Testing needs the command-line tools its instructions call (java). Our summary lists: Python 3.
Does Deserialization Testing access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Deserialization Testing safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Deserialization Testing use?
No licence was found for Deserialization Testing or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Deserialization Testing use?
About 836 tokens (SKILL.md is roughly 3.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Deserialization Testing?
Skills that share tags, products or a category with Deserialization Testing: Insecure Deserialization Playbook (PentesterFlow/agent, 1.4k stars), Ssti (PentesterFlow/agent, 1.4k stars), Hunt Deserialization (Encod3d-Sec/TORCH, 329 stars) and Dt Obs Services (Dynatrace/dynatrace-for-ai, 161 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Deserialization Testing?
NeoTheCapt (a GitHub user) maintains it in NeoTheCapt/RedteamAgent, which has 140 GitHub stars. The repository holds 25 skills in this directory. The repository was last updated on August 2, 2026.
Source: NeoTheCapt/RedteamAgent on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.