This double spender mod actually finds other NODES with MODDED Bitcoin-qt wallets and cooperate with them to slightly FORK Blockchain to make outgoing transacitons only in FORKED blockchain (Keeping your Bitocins in Original blockchain).
All modded bitcoin-qt wallet NODES then cooperates to "convince other nodes about outgoing transactions".
Success rate is quite good and takes no longer then 1 hour to convince enough nodes.
Download also contain some blockchain explorrer and other stuff
