Malware attacks against Internet of Things (IoT) and Operational Technology (OT) devices have increased by 400 per cent this year when compared to the previous year, a new report showed on Wednesday. The report by the cloud security company Zscaler, which analysed approximately 3,00,000 blocked attacks on IoT devices over a six-month period, highlighted the relentless nature of cyber threat actors, revealing that attackers are primarily targeting legacy vulnerabilities.