COMPUTER users are being urged to guard their systems against cyber attack after a Stroud woman became the latest victim of the international Trojan Horse virus Cryptolocker.

The virus locks down computers and hackers then demand cash to redeem the files.

Cryptolocker is a virus which encrypts the files and demands a ransome for the return of your data, however this may not always be the case.

The warning comes in the wake of another Gloucestershire woman who had £40,000 taken out of her account by online hackers.

This week IT specialists confirmed other victims in the county have fallen prey to the scam and lost tens of thousands of pounds through internet fraud.

“We have heard of cases where the data was unlocked but then after a short period of time and without having the system cleaned the data was then locked down again,” said Jamie Dickinson from The Computer Shop in Stonehouse.

64-year-old Jo Wickes of Stroud discovered her computer was locked when a message popped up on her screen telling her to download Cryptolocker.

Had she clicked on the link she would have been directed to a web page and asked to pay money to have her files restored.

“I don’t do any online banking or anything along those lines that would allow hackers to access my bank details. I only really use my computer for emails,” said Ms Wickes who has taken her computer to Mr Dickinson to be wiped clean.

“The only thing I can do for Ms Wickes now is wipe her computer completely. However, I cannot guarantee it is not possible to catch this again by making one simple mistake,” said Mr Dickinson.

And he stressed: “It is important to note that if people click on the link and pay the fee, not only may the data not be released but there is a danger people may give the scammers more information than they already have.”

Ms Wickes became suspicious when a message appeared on her computer saying she needed to renew her McAfee anti-virus software.

“I knew that this was not right as it is not due to run out until at least September,” she said.

Although she is relieved no money has been stolen, Ms Wickes is not sure yet whether everything will be lost from her computer.

The Government’s UK National Crime Agency has urged people to back up their files and photos on external hard drives.