I guess it's some sort of differential backup + archiving - lots of system files are just lines of code which compress rather nicely.
Um a quick google would show you it is. Its just hidden due to being a system file
Just Roxio Go Back uses that folder name structure to store its backups and was a pain in my neck for a few days a couple of weeks back on a HP laptop. Might want to check that didn't cause the problem as removing the folder isn't enougth if it is Roxio. It will just start again.