Unless you've been living under a rock for the past 48 hours, you will likely be aware that a cyber attack crippled thousands of computer systems across the world from last Friday onwards.

But what exactly is the malware known as WannaCry all about?

So, WannaCry is a particularly heinous form of ransomware which encrypts files on a computer rending them inaccessible, and ultimately holds the owner to ransom by only unlocking the files after the user pays a ransom in Bitcoin.

Since last Friday, the malware hit more than 200,000 machines in 150 countries, including multiple large organisations lke the NHS in the UK, the National Petroleum Corporation in China and Renault factories in France.

While report circulated that the attack had come to an end after a 'kill switch' was triggered on Saturday, this is not the case.

While the switch did, indeed, slow the attack down, researchers confirmed that a new version of the malware had not been affected by the triggering of the switch.

"It's this constant battle," said Ryan O'Leary, vice president of WhiteHat Security's threat research centre. "The bad guys are always one step ahead."

Fortune advises the public to exercise extreme caution when opening emails, and recommends that those who use older versions of Windows should install Microsoft's new security update.