NewsFactor - A researcher at security software firm Kaspersky Labs has uncovered a sophisticated botnet threat that already controls more than 4.5 million Windows-based PCs around the world, with nearly one-third of all infected machines located in the United States. Moreover, there is reason to believe that the latest strain of TDSS uncovered this week -- which commands the infected PCs to run malware programs -- will be able to evolve over time.