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.
More than a million computers around the world have been hit by a powerful malware designed to infect computers and mine them for valuable information.
The FBI said users should check for the following symptoms if they fear their computers could have been attacked by the GameOver Zeus malware:
Around 15,500 computers in the UK have been hit, the National Crime Agency said.
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.