Does it make sense to scan Software CDs/DVDs before installing?

Factual Questions
1

I just tried it with Norton antivirus on a Fix-It Utilities CD. Surprise, surprise, no surprises; no viruses, etc.

But knowing less than nothing about such things, I wonder if malware in the compressed state is recognizable to detection software?

If the answer is “That depends…” could it be that just like unzipped malware, you’ve got to run it past various programs to have a reasonable chance of catching the little bastards?

Or what?

2

Any decent virus scanner can look inside compressed archives, as long as they aren’t password protected. Exactly which formats are supported is another question… ZIP should be supported, but CAB (many Windows installers), RAR, and self-extracting archives may not be.

3

Assuming the software isn’t password protected, is there a scan, or some other method, to determine the compression format - ZIP, CAB, RAR - before you install it?

4

And what kind of reading might I get with Norton, if the compression format isn’t supported? Would Norton come back with something to the effect: “Sorry, but I can’t read this stuff!”?