Online gambling was the top industry sector targeted by ransomware last year, according to a new report.

The 2018 Global Threat Intelligence Report by global cyber resilience firm NTT Security found that the volume of ransomware – the malicious blocking of access to data unless payment is made – surged 350% in 2017, accounting for 7% of all global malware attacks last year.

The gaming industry was the target of 20% of all ransomware attacks last year, higher than the business & professional services (17%), health care (12%), manufacturing (12%) and technology (11%) sectors. Two types of ransomware, the Locky trojan and WannaCry worm, accounted for 45% and 30%, respectively, of all such attacks in 2017.

NTT described ransomware as the “weapon of choice” targeting gambling operators in the Europe, Middle East and Africa (EMEA) region, which accounted for 36% of all such attacks in 2017.