Don’t download from a shady looking website, go to reputable sources. Fitgirl, Internet Archive, etc. Read the comments if the website has them, don’t have to read thoroughly, just a quick skim to see if other people reported things and whether they’re false positives. Don’t download things before they’ve released, or download things for other platforms but "for Windows"somehow. Make sure what you’re downloading takes up the kinda space you’d expect from that game, (don’t download GTA V but it’s a 40mb download).

Yeah, we basically rely on blind faith. Honestly I trust pirates to keep their stuff clean more than the developers and the publishers themselves who just so often inject the malware called DRM in the first place.