Microsoft has named a pair of men already serving jail terms in the UK as defendants in its suit over the Zeus botnet.
The company added Yevhen Kulibaba and Yuriy Konovalenko to an earlier complaint which had previously been limited to aliases and 'John Doe' defendants. Both men are currently serving time in jail for hacking in to bank accounts.
The complaint, originally filed in March, alleges that the men acted as part of a group which harvested user account information.
The Zeus malware has become a favoured tool of cybercriminals for collecting account credentials and other information from users. The infection allows a remote attacker to directly embed code into local HTML files, giving the attacker the ability to turn otherwise legitimate web pages into phishing tools.
While Microsoft has acknowledged that the complaint and subsequent takedown effort would not fully eradicate the Zeus malware, the company reported that known Zeus infections were down from 779,816 to 336,393 between March and June.
"Microsoft and our financial industry partners sought to help protect innocent people by disrupting the Zeus business model and increasing the cost of doing business for cybercriminals," Microsoft digital crimes unit senior attourney Richard Boscovich said in a company blog post.
"I'm happy to report that we are already seeing proof that our disruptive actions were successful in achieving this goal."