In an international operation coordinated with multiple law enforcement and industry partners, Europol led a take down of the infrastructure of the Ramnit botnet that infected 3.2 million Windows computers. Ramnit is a strain of malicious software called a bot that the cybercriminals used to spy on PCs and steal information such as banking and social media passwords.
A botnet is a collection of bots (also called zombies) controlled by cybercriminals, who can rent out their bot army to other crooks for nefarious purposes.
The malware was first identified by Symantec, Microsoft and an IT security company Anubis Networks; who further reported it to law enforcement agencies in Europe. The Europol with the help of European Cybercrime Centre (EC3) then destroyed and shutdown the command and control servers for the malware.
The botnet spread around the internet by posing as normal web links and files. It was hidden in emails and sent via social networks, spreading using computers that it took control of.So beware of this and be careful with malicious links and emails containing attachments.