The shoes are called 'New CAS Project'
Launcher pic looks like this: http://a.imageshack.us/img441/714/newcasprojectshoes.png
Number in DCBackup: 0x84bf695c34fa680fe8c899a4ca3da53a
Are the shoes actually used on the sim ? For they are not 'bad' in any way I can tell without trying in the game. If so, they get packed (that's what sims3packs do).
Everytime you install something the sims3pack gets unpacked into the DCBackup folder. This are store items as well as other cc. Since it does not serve much purpose you can just delete everything in there.
every download gets installed into the *.dbc files, so they grow when you install anything (this is your installed content). *.ebc are all your store items. Since the files don't get bigger as a certain size (you can tell the game somewhere how big those files can be) a second file is created once that size is met. If you delete your *.dbc files all your cc will be gone (except houses and sims).
