Back in October of last year, a new strain of ransomware, known as Cryptolocker, emerged as a threat to all home and business computers. Once infected, all of the files on a computer would become encrypted – locking the user out of all files and rendering the PC virtually useless.

Infected PCs would display a message informing the user that the decryption key required to unlock all of the files, would be destroyed within 72 hours, unless a ransom of around £300 was paid in order for the use to retrieve it.

Businesses with good business continuity plans in place from their IT support providers were not too drastically affected if they became infected, as systems could be easily restored from one of their recent backups. However, some smaller businesses and home users were hit hard.

Recent breakthrough in the fight against Cryptolocker

Now there’s good news for victims of the Cryptolocker and GameOver Zeus malware. Security experts at Fox It and Fire-eye, have developed a free online tool designed to decrypt files locked by the Cryptolocker virus.

All a user needs to do is upload an encrypted file (that does not contain personal information) to the free online tool, and use the master decryption key and recovery tool that is provided to unlock all files on the system.

Of course, this is more likely to be of use to owners of personal home computers than businesses, who should have been able to restore their systems from regular backups provided by their IT support company.

It is estimated that Cryptolocker claimed around 500,000 victims – and the 1.3% of people who opted to pay to receive the decryption key have together raised around £1.3 million for the criminal gang responsible.