Malicious Mods?

I tried to find some information about this in the wiki/mod list, but wasn't successful:

Are mods for VS capable of causing harm for your machine or are they "sandboxed" in the game? Since parts of the base game are created as mods, I feel like they're quite powerful.

If they are not sandboxed, is it save to download them from the mod list (are they checked in any way)?

As I now heard multiple times, even the base game is flagged by some anti virus software, so this probably isn't a good indicator as well.