In the world of gaming and archival, a .rar file with a naming convention like sc24651 usually indicates one of three things:

Someone is "time-stamping" a specific version of the game. Because digital games update automatically on Steam, purists often save specific versions (like v1.1.1) to ensure their favorite mods continue to work or to speedrun on a specific "patch" [2, 3].

Are you looking to a specific mod from this archive, or are you trying to recover an older save file?