Zeus, a virus that steals online banking details from infected computer users, is more powerful than ever. That word comes from Trusteer, a web security company, the BBC reports. The Trojan virus in one of every 3,000 of the 5.5 million computers it monitors in the US and Britian, the company says. Zeus 1.6 can infect people using Firefox and Internet Explorer web browsers. The malware steals login information by recording keystrokes when the infected user is on a list of target websites. These websites are usually banks and other financial institutions. The user’s data is then sent to a remote server to be used and sold on by cyber-criminals.