Ransomware attacks are on the rise, and now account for around a quarter of cyber threats targeting internet users in the UK, according to security firm Eset.

Eset’s LiveGrid telemetry shows a spike in detections of the JS/Danger.ScriptAttachment malicious code, which tries to download and install various malware variants to the intended victims’ machines.

The majority of the code consists of crypto-ransomware, including some well-known groupings, such as Teslacrypt.

The most recent wave of attacks has been focused on victims in the UK, where it accounted for roughly every fourth threat in the third week of April 2016, said the security firm.

“To reach as many potential victims as possible, attackers are spamming inboxes in various parts of the world,” said Ondrej Kubovič, security specialist at Eset. “Therefore, users should be very cautious about which messages they open.”

Ransomware going “crazy” Meanwhile, the latest Verizon Data Breach Investigations Report (DBIR) also warns that ransomware attacks are steadily increasing. Laurance Dine, managing principal of investigative response at Verizon Enterprise Solutions, said: “Ransomware is going crazy. It is everywhere. As an incident response team we are dealing with ransomware attacks all the time.” Eset’s Kubovič recommends that companies should train their employees to report incidents to their internal security departments. “Users should keep their operating systems and software up to date, as well as install a reliable security suite offering multiple layers of protection and regular updates,” he added. “Last but not least, users need to back up all their important and valuable data, allowing for its recovery in case of ransomware infection,” he said. While ransomware is becoming an increasing problem for businesses, a recent spate of attacks on hospitals in the past few months – mainly in the US, but also in Canada, Germany and New Zealand – has underlined the potentially life-threatening impact of ransomware, which works by encrypting data and demanding a ransom to be paid for its release.