File-encrypting ransomware has eclipsed botnets to become the main threat to enterprises, according to Trend Micro.

During the fourth quarter of 2015, 83 per cent of all data extortion attacks were made with the use of crypto-ransomware.

CryptoWall topped the list of 2015’s most notorious ransomware families, with a 31 per cent share. According to FBI statistics released last June, CryptoWall managed to generate more than $18m for its creators in a little over a year.

These revenues – traced by monitoring BitCoin wallets and similar techniques – provide evidence that a growing percentage of organisations affected by ransomware attacks are paying up.

Healthcare is the most affected sector when it comes to cyber-attacks more generally, according to other findings from the 2015 edition of Trend Micro’s Annual Security Roundup Report. Throughout 2015, almost 30 per cent of all data breaches happened in the healthcare sector, followed by education and government sectors (17 per cent and 16 per cent, respectively).

Elsewhere, businesses at increased risk from the Internet of Things (IoT) attacks which are moving on from becoming something only consumers need to think about as wearables and the like enter the workplace, Trend warns.

Given their susceptibly to attacks, IoT devices within the enterprise ecosystem can become liabilities. Unlike Android devices, which already have fragmentation problems of their own, IoT devices run on several different platforms, making device and system updates as well as data protection more complex than ever.

More from Trend’s study, published on Tuesday, can be found here. ®