According to the NCA, the UK now has two weeks to protect itself and stop hackers accessing sensitive information.
They advise all computer users to use this time to safeguard themselves by updating anti virus software and checking that applications on computers are running correctly.
The virus – which was first uncovered by the FBI in America – could cost the UK millions of pounds.
Andy Archibald, from the NCA’s National Cyber Crime Unit, has urged people to take action, saying to the Mirror:
“Nobody wants their personal financial details, business information or photographs of loved ones to be stolen or held to ransom by criminals. By making use of this two-week window, huge numbers of people in the UK can stop that from happening to them.
Whether you find online security complicated or confusing, or simply haven't thought about keeping your personal or office computers safe for a while, now is the time to take action.”
If you need free anti-virus software or advice, awareness group Get Safe Online have set up a help centre on their webpage which you can access, here.