The surging price of Bitcoin, now worth about $5,630 per coin, has led to the creation of several coin-mining systems.

Many sites are now hosting a code that secretly uses a visitors' computer to mine the valuable e-cash coins.The code is inserted by hackers who exploit poor site security or web software bugs.

BBC reported that hundreds of websites were found to be running code created by the Coin-Hive project . This let the web domains generate coins for the Monero crypto-currency by using the processing power of visitors' computers.

While some sites had put the Coin-Hive code on their site themselves, many others had been hacked to host the short script.

Some of the coin-mining programs specifically target popular website creation and admin systems such as WordPress. Others are written in Javascript and their creators try to insert them wherever they can.