Botnet Waledac, a network of hijacked PCs among the top ten botnets globally and a leading producer of malware and spam, has been facing a potentially severe challenge from Microsoft, the biggest software company worldwide. According to Microsoft on February 25, 2010, court granted it a judgment wherein the '.com' registry, VeriSign, will have to delete 277 domains featuring '.com' from its lists. Consequently, the link between the operators of Waledac and the botnet's infected PCs will be effectively snapped, the software giant reports.