The National Crime Agency is warning people they have two weeks to save their computers from a powerful malicious software attack. The malware called GOZeuS is hiding within attachments in emails and, once downloaded, enables hackers to access computers and scan them for valuable information.
If no data is found, a second malware, known as CryptoLocker, locks the computer, displays a window with a countdown, and demands a ransom to grant access again.
According to the NCA, people are asked to pay 1 Bitcoin (£200 - £300) to regain access to their files.
The NCA is advising people to make sure security software is installed and updated, by running scans and checking that computer operating systems and applications are up to date.
Sales of the personal computer have dropped by 10 per cent in the past year as the tablet market continues to rise.
Editor of PC Pro magazine Barry Collins told ITV News: "(Tablets) are just a really nice experience compared to a PC where you have to wait 10 seconds to boot up or it might upload an update".
Police in Australia say they have arrested a man closely linked to the international computer hacking group LulzSec. The action was taken after a Government website appeared to come under attack.
The 24-year-old IT worker, whose name has not been released, was arrested on Tuesday night at his office in Sydney. Police say the man claimed to be a high-level member of the LulzSec hacking group.
He is facing charges of altering data and accessing restricted information. If convicted, he could face up to 12 years in jail.