They're the spawn of the devil
Over the years I've installed probably hundreds.
They generally come in 2 types....'scr' or 'exe'....where the latter is 'the installer for the brain-dead novice' who doesn't know where to put a scr file. [either in /windows or /windows/system32 will work, btw].
Both forms are executables and thus 'can' easily have an evil payload [virus/trojan/key-logger] so MUST be installed during the moderation process so their 'safety' can be checked by the host up-to-date AV proggies, etc.
So....there I was last night....2 scr's and an exe to look at.....and downloaded all 3.
The scr's can be executed from within the zip....quick and easy to try out...and once deleted do nothing to system settings.
The exe is an installer....needs to run and merrily will put a scr in a system folder...or will put it in its own location of choice and set its location via a standard registry entry....and often will simply alter your default screensaver option to point to this new one. Because you then NEED to uninstall after testing it's often ignored/left for 'ron'.
I did this testing around 1.00 am my time. [I do both long and odd hours here]....and hit the hay relatively early [1.15].
Now, my 'normal' scr settings are for 'blank' after 15 minutes....but now they were different....
1.30 am I'm in bed, dozing off and a 'noise' starts up....seems like it might be someone watching a home cinema nearby....so I ignore and drift off.....only to be awakened by Terry [my missus] getting up and saying 'your computer is making funny noises'...so I'm awake again.
I get up and sure enough...it's a repetitive noise that certainly isn't winamp doing a wobbly....it sounds like a bunch of hornets on a wonky loop audio track.
A mouse-move later and it's instantly stopped.
'effing savers', I mumble....and pop open the properties to reset to 'BLANK'.
Now it's pushing 2.00 am....and Terry gets up for work at 5.30....yippee.
You know, screensavers were intended [as the name implies] to save monitor screens from burn-in caused by displaying a static image for a long time [unattended computer left on]...but technically your speakers don't suffer the same issue....so there's really no need for an audio track....but if you're really wanting one....make it something sleep-inducing....
That'd be nice....