Wiltshire Police, along with the National Fraud Intelligence Bureau (NFIB), are warning of a large-scale computer virus.

The NFIB have been made aware of a destructive malware which installs itself on to computers and encrypts the users’ files.

It then sets a time limit for which it requires payment to release personal data back to the user. If the time elapses without payment, the private key is destroyed and the personal files permanently disabled. This has become known as ‘ransomware’.

The cyber criminals responsible for creating the ‘Cryptolocker’ malware originally targeted businesses but are now focussing on home internet users who have a Windows system on their computers.

Det Sgt Jon Lee, head of Complex Fraud at Wiltshire Police, said: “Innocent members of the public are being tricked into installing this malware onto their computers and are then financially blackmailed for access to their own personal data.

"Things like music, photos and important documents all become blocked and, unless the malware is removed, that person may never have access to any of their personal data again.

“I would urge the local communities to be vigilant towards this particular type of cyber crime and take the necessary preventative measures to stop themselves from becoming a victim.

“Simple tips like ensuring that you don’t click on unsolicited email attachments, backing up your files and storing them offline, and updating your anti-virus software will all help to eliminate the chances of your computer being targeted.

"It’s also really important that you don’t send any payment to these people.

"This only fuels the problem and there is no guarantee that the criminals would unlock your access to the data anyway.

“We work closely with the National Fraud Intelligence Bureau, Action Fraud and the National Crime Agency to ensure that we are exchanging information to identify and bring those responsible to justice.”

To report this or any other type of fraud or attempted fraud, contact Action Fraud via www.actionfraud.police.uk or by calling 0300 123 2040.