How to distinguish between a PE installer and a normal executable file

[towatowa]

How can I tell if it's an installer file or a regular executable program, and where do I look for the code?

[horsicq]

Hello! The source code for the whole project: https://github.com/horsicq/DIE-engine
Signatures: https://github.com/horsicq/Detect-It-Easy/tree/master/db