The original concept was a screensaver for Macintosh, which was soon after ported to X Windows as "Xsnow". Several different versions were made for Windows. Here's one: https://janswaal.home.xs4all.nl/WinSnow/
Found the tool I was talking about after searching in my backup drive with old stuff. It was a small tool df_snowfall from 2006 downloaded from a now defunct warez site www.darfun.tk. Might have downloaded it along with some other software. Windows 10 kept complaining it's a trojan and didn't run it correctly even with compatibility mode.
