Bangladesh, Sept. 11 -- In one of the most high-profile cybercrime pursuits in recent years, European and American authorities have escalated their hunt for a Ukrainian fugitive believed to be the mastermind behind a ransomware syndicate responsible for billions of dollars in damages worldwide. Volodymyr Tymoshchuk, a 37-year-old Ukrainian national, has been placed on the European Unions Most Wanted list, accused of orchestrating the deployment of LockerGoga, MegaCortex, and Nefilim ransomware strains that crippled industries, disrupted supply chains, and exposed sensitive data across multiple continents.

The move marks a major escalation in transatlantic cooperation against ransomware groups, which officials now describe as one of the g...