MERSEYSIDE Police are backing a campaign urging computer owners to take urgent steps to protect themselves from malicious software known as 'Malware'.
The National Crime Agency believes 15,500 computers across the country are infected with the software, called GOZeus and Cryptolocker.
GOZeus allows criminals to spy on your internet activity, often leading to a victim's bank account being emptied through fraudulent online activity. Cryptolocker encrypts people's computers, then demands a ransom for them to be unlocked.
Action is being taken over the next two weeks to disrupt and weaken the global network of infected computers, meaning people across the country will have a chance to take some simple steps to protect themselves.
These include updating their operating system and regularly checking for updates, installing and updating anti-virus and security software.
This can be free for a basic level of protection, being careful about clicking on links in unsolicited or 'spam' e-mails.
This is one of the most common ways that computers get infected and changing their passwords to make them harder to guess, using a mix of numbers, letters and other characters.
Detective superintendent Richie Carr said: "Computer problems can seem daunting for lots of us but help is out there and I would urge people to take this opportunity to strengthen their security measures and protect themselves.
"There are some really good sites on the internet which people can go to for help, advice and tools to clean up their computers, including www.getsafeonline.org
"If people think their computer is infected with any malicious software they can report it to www.actionfraud.police.uk. They should also tell their bank and change all their passwords."
GOZeuS, also known as P2PZeuS, has been assessed as being responsible for the fraudulent transfer of hundreds of millions of pounds globally.
Andy Archibald, deputy director of the NCA's National Cyber Crime Unit, said: "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.
"Our message is simple: update your operating system and make this a regular occurrence, update your security software and use it and, think twice before clicking on links or attachments in unsolicited emails.
"Those committing cybercrime impacting the UK are often highly-skilled and operating from abroad.
“To respond to this threat, the NCA is working closely with law enforcement colleagues all over the world, and developing important relationships with the private sector."