The UK has a "two week period" to protect itself from a major computer virus that could give hackers access to sensitive information - costing the country millions of pounds, the National Crime Agency has said.
The design of a new powerful malware makes it "nearly impossible" to completely wipe out, but a coordinated response by the authorities can control it, computer security expert said.
Lamar Bailey, director of security research and development at software company Tripwire, said countries are rolling out a programme to clean up infected computers, asking users to update their security systems.
Computer users are constantly being told to change passwords and update software due to the latest "Trojan" or "Bot" - but what are they?
The malware, called GOZeuS is hiding within email attachments, and once downloaded will enable hackers to mine infected computers.