Bitfloor's servers were breached and hackers accessed an unencrypted backup of Bitcoin wallet keys. The founder, Roman Shtylman, had failed to encrypt the digital wallet containing encryption keys during a system upgrade, leaving the backup in unencrypted form on disk.

Bitcoin exchange Bitfloor suspended operations after the theft of $250,000. The founder Roman Shtylman explained in a post on the Bitcoin Forum that an attacker obtained an unencrypted backup of exchange wallet keys and used these keys to transfer "BitFloor on hand" Most of the coins he held," Shtilman later locked this part of the money at around 24,000 BTC.