Always scan .zip files from unofficial sources with antivirus software before extracting, especially if they contain .exe or .dll files.
If the file size is small (a few MBs), it likely contains player progress. You would see folders named 000001 - QuickSave containing .sav and .rim files. File: Star Wars - KotOR.zip ...
If the file is several gigabytes, it is likely a backup of the game installation. A legitimate backup would contain the swkotor.exe , data folders, and Miles sound drivers. Always scan