> For the complete documentation index, see [llms.txt](https://dmcxblue.gitbook.io/red-team-notes-2-0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dmcxblue.gitbook.io/red-team-notes-2-0/red-team-techniques/defense-evasion/t1036-masquerading/invalid-code-signature.md).
# Invalid Code Signature
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. Adversaries can copy the metadata and signature information from a signed program, then use it as a template for an unsigned program. Files with invalid code signatures will fail digital signature validation checks, but they may appear more legitimate to users and security tools may improperly handle these files.
Unlike Code Signing, this activity will not result in a valid signature.
**Example**
CarbonCopy a tool built by paranoidninja for spoofing Digital Signatures, signatures like these can actually bypass AV and pass undetected by analysts because they provide a level of authenticity. See 2 payloads with and without a Digital Signature.
Now will check out the digitally signed one a little more to check what it contains.
A Digital Signature not installed of course this is why we see that it cannot be verified.
We have the option to install this certificate of course with proper permissions but here I am just trying to demonstrate how this "Signature" can provide some level of authenticity since it is Signed by Microsoft, of course a solid analyst can see that this has been valid from a recent Date. So how can we build this digitally signed binary, with CarbonCopy.
Above we see a successful spoofed Signature the requirements for this is very simple the website we are trying to spoof its signature the port the target payload and an output file.
**You will also need OSSLSignedCode tool to be installed.**
References:
{% embed url="" %}
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://dmcxblue.gitbook.io/red-team-notes-2-0/red-team-techniques/defense-evasion/t1036-masquerading/invalid-code-signature.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.