hunting-dotnet-deserialization-type-injection SKILL.md skillA
hunting-dotnet-deserialization-type-injection from unboundcompute/security-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add unboundcompute/security-agent-skills/hunting-dotnet-deserialization-type-injection@git:20260826.c45369bPins git:20260826.c45369b in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- unboundcompute/security-agent-skills
- Path
skills/hunting-dotnet-deserialization-type-injection/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260826.c45369b, committed Aug 26, 2026
- Size
- 9,006 bytes
- Repository stars
- 26
- License
- MIT
Hunt .NET deserialization where untrusted input reaches a formatter that resolves the type from the data itself: BinaryFormatter, SoapFormatter, NetDataContractSerializer, LosFormatter or ObjectStateFormatter on ViewState, or Json.NET and similar with type-name handling enabled. Covers formatters that instantiate an attacker-named type and drive a gadget through a set accessor, a callback, or a converter to a command, a process start, or a file operation. Use when a service reads serialized…
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
# Hunting .NET deserialization and type injection: when the payload picks the type .NET deserialization is dangerous for a specific reason: several formatters read the concrete type to instantiate from the serialized data, not from the declared target. When `BinaryFormatter`, `SoapFormatter`, `NetDataContractSerializer`, the ViewState formatters, or a JSON serializer with type-name handling turned on processes attacker data, the attacker chooses which class gets constructed. That lets them instantiate a gadget type whose property setters, deserialization callbacks, or type converters perform a side effect, chaining to a process start, a command, or a file operation. The fix is almost always to stop resolving types from the data. You find these by locating every formatter that honors an embedded or annotated type and asking whether untrusted bytes reach it. ## When to use - A service reads serialized .NET objects from a request, ViewState, a cookie, a queue, or a cache. - A formatter in use resolves the type from the payload or has type-name handling enabled. - Reachable assemblies carry a gadget type whose construction or callback has an exploitable side effect. ## Scope check …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/hunting-dotnet-deserialization-type-injection@sha256:01ccaff34cf1b05fThe line at the top of this page pins the label git:20260826.c45369b, 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_a72ccbafcbsh7w2t)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Aug 26, 2026.
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 (9006 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
unboundcompute/security-agent-skills · 26 stars · license MIT · pushed 2026-09-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_a72ccbafcbsh7w2t GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/hunting-dotnet-deserialization-type-injection GET https://markdownregistry.com/api/v1/blob/01ccaff34cf1b05ff709c5be21d1a17001c2b2ffdb1b72493d0b822aaa0ecd5e
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.