Is it possible to create a similar "capture" program that simply captures and returns the btc back to the sender, along with some sort of message that can be used to flag the transaction? This way, over time, it will be easier to determine the source of the code.
Nice idea, but not a good one.
Sending coins back to the address they came from could just end up losing the coins permanently, because now days wallets do not re-use addresses, and the original owned might not have that address in his wallet anymore.