Large UK companies are amongst the hardest hit by ransomware in western countries according to a new report commissioned by Malwarebytes. The report found that more than half of large firms had been affected—and that nine percent had been left "entirely unable to operate."

Ransomware is clearly a growth industry in Britain: 58 percent of IT directors in this country have paid ransoms in the past, and the UK experiences more attacks than the Canada, Germany, and the US. American bosses are 21 times less likely to give in to hackers' demands than their UK counterparts.

Ransomware is malicious software that uses tough encryption to lock users out of key files or their entire system until the owner pays up. It's a relatively simple scam that is rapidly gaining popularity, according to Malwarebytes. The vast majority of attacks are coming through an endpoint, with 46 percent originating from an e-mail.

A lot of it is on the smaller end of the scale: around 60 percent of attacks asked for over $1,000 (£750), but more than a fifth demanded $10,000 (£7,500) or more, with one percent swinging for the fences and aiming for a payout of $150,000 (£113,000).

Malwarebytes ransomware expert Nathan Scott said that the "current prevalence and ramifications" of the recent rapid growth of the problem had not previously been thoroughly explored. He added:

Over the last four years, ransomware has evolved into one of the biggest cybersecurity threats in the wild, with instances of ransomware in exploit kits increasing 259 percent in the last five months alone. The impact on businesses around the world has been significant.

Malwarebytes spoke to 540 CIOs, CISOs, and IT directors from companies with an average of 5,400 staff across the US, Canada, UK, and Germany—and discovered that nearly 40 percent of these businesses had been hit. It found that in 3.5 percent of instances, lives were put at risk when ransomware put systems out of action, with healthcare and financial businesses the most frequently targeted.

British companies are also the least likely to know the source of the attack: 22 percent of those surveyed had no idea how they were attacked. Training is also an issue, as UK firms are the least likely to stump up for it; for nine percent of firms hit by ransomware their entire systems had been locked down, suffering total operational blackout until a ransom was paid. According to the report, this didn't happen at all in the US and Germany.