How does Windows decide whether to display the UAC prompt?

Question

In my VB6 application I open other EXE files. My application runs without any UAC prompt, but I have an EXE which checks for updates to software. This prompts the UAC prompt

Answer 1

Your programs probably lack application manifests that mark them as non-legacy. As a result Windows will apply scripted installer detection heuristics to decide whether your program is an installer. This is pretty much the only way an "unexpected" UAC prompt gets raised.

These heuristics include keyword searches within the EXE file name and several of the extended properties of the EXE, and may even look for well-known binary signatures (i.e. byte strings) inside the file.

BTW, your crypto-signing doesn't enter into this at all. And it doesn't help a thing if it wasn't issued by a trusted CA.

For that matter anyone who trusts code just because Windows reports the commpany name on the UAC prompt is a fool. Malware authors steal these all the time, and for that matter they are trivial to obtain and almost never reported by users when crap programs cause problems. Save your money, code signing certs are a failed concept.