[colejohnson66]

IIRC, 7-zip does tell you if the actual format is different. At least it does when I extract some DMGs; it tells me it's actually an HFS "file".

[paulfr]

Not on Windows, at least. The properties dialog can tell you it uses HFS+ if you ask for it, but it's too late because the HFS+ code has already been executed.

[colejohnson66]

I meant when right clicking the archive am choosing "Extract to..." or something using Explorer's context menu.

[paulfr]

Interesting, it does display a warning in this case! But it doesn't interrupt extraction so if it's a malicious file the code will still execute.