http://krebsonsecurity.com/2013/07/botcoin-bitcoin-mining-by-botnet/Bitcoin is a decentralized, virtual currency, and bitcoins are created by large numbers of CPU-intensive cryptographic calculations. As Wikipedia explains, the processing of Bitcoin transactions is secured by servers called bitcoin miners. These servers communicate over an internet-based network and confirm transactions by adding them to a ledger which is updated and archived periodically using peer-to-peerfilesharing technology. In addition to archiving transactions, each new ledger update creates some newly minted bitcoins.