and after I unpacked it, Avast went crazy and MSC command line showed up with several other empty windows. I wasn’t able to do anything in Unity as it froze. I have no idea what happened there, but is there a possibility of the texture pack from the link above being a some sort of a virus? I haven’t had any problems with downloading tens of packs like this…
I think I’ve seen the behaviour you’re talking about; it’s a rare bug in Unity’s package importing code which, for some reason, causes a load of windows on your system that are normally hidden to be set as visible. The pack that you’ve downloaded should be fine.