Trickbot's malicious software at one point was counted among one of the internet's most pernicious security threats, capable of stealing financial data, spreading across networks, and dropping ransom software.

The group behind it was seen as particularly ruthless. In its announcement, the Treasury noted that, "during the height of the COVID-19 pandemic in 2020, Trickbot targeted hospitals and healthcare centers, launching a wave of ransomware attacks against hospitals across the United States."

Reuters could not immediately locate contact details for the alleged hackers named by the Treasury.

The Treasury said the sanctions applied to Trickbot's senior figures and managers. Targets of such sanctions are generally barred from holding U.S. assets or transacting with American organizations. However the measure is often largely symbolic given ransomware operators tend to operate well out of reach of U.S. officialdom.