Can Steam Cloud Save Files Carry Viruses?

Steam Cloud only stores your save files and game settings, not any executable files. So it's very unlikely that any virus from your previous infection would be hiding in there. The real danger would be if the malware intentionally altered your save files, which is super rare. Just download Steam again, make sure your antivirus is up to date, and you should be just fine.

Bigger companies have made mistakes, but Valve usually does a good job of keeping their environments secure. The chance of any harmful files being stored in Steam Cloud is very low.

Possible? Yes. Likely? No. Just go ahead and reinstall, you should be okay.

In theory, yes, it’s possible for a virus to manipulate files, but practically speaking, that’s not how you got infected in the first place. Most likely, you’ve got nothing to worry about.

It's possible, but not likely. You really think Valve would let infected files slip through? They’ve got a good track record, and the type of files that sync are a low risk for being dangerous.