Abandonware has no legal meaning. Just because the owner of an IP is not currently selling it does not mean that they don’t own it. Even the games that were publish by companies that no longer exist doe not mean that no one owns them. Sierra may not exist anymore, but Activision owns most of the old Sierra IP. And in particular, The PQ games are currently being sold. You can still get the 2006 VU collections and the game can be bought on Steam as well as GOG.
On top of that, these pirated games often have issues from having parts ripped out, like speech, being cracked or altered in other ways to the point that can create unpredictable bugs and crashes. And this is assuming that the archive has not also been pack with malware.
It does not make much sense to download it from an illegal site when you can legally buy all 4 PQ games from GOG for only $9.99.