Often used in the Linux community, (sometimes apple but who cares about dem apples) a TarBomb is a set of files compressed into a single archive (much like a .zip on windoez) this file, when decompressed either contains file locations that cause the file to essentially projectile vomit, explode, and rape all your files while throwing itself all over your computer taking up redonkulus amounts of space and whoring all your folders, and often overwriting many of your documents.
tarbomb in action:
Billy: "Man, I found this awesome software last night!"
Joe: "Really? can you send me it?"
Billy: "Sure man, here you go! its only 30mb =]]]"
Joe: "Wow thanks! this will make my life so much easier."
----THE NEXT DAY----
Billy: "How'd it go? =D"
Joe: "You douche bag! when i unpacked it my processor melted, my hard drive is full, all my stuff for work and all my pictures and music were deleted, im going to ****** kill you!"
Billy: "Hah! cool story bro, tar-bombed idiot. =DD"