The Spanish Civil Guard has arrested three men behind one of the biggest botnets in recent history, which infected 13 million computers with software designed to steal private data such as credit card numbers.
The Mariposa botnet had infected computers in 190 countries, with organisations such as schools, government agencies and major corporate affected.
It is not yet known how much money has been stolen as part of the botnet, but some experts have said removing the programs from various machines could cost millions.
The program was designed to take control of infected machines, record keystrokes and use login details to steal cash and other private data, which was sent to a type of control centre.
The virus was spread using vulnerabilities within Microsoft’s Internet Explorer browser.