Kelihos Botnet Makes A Come Back

Microsoft recently acknowledged that a new variant of Kelihos botnet is being reassembled. Spam from the botnet underlines that taking down its DNS server alone is not effective in killing off botnets. Security experts suggest that only patching infected machines or taking botnet controllers out of circulation would be truly effective. At its peak, Kelihos spewed out as many as 4 billion junk mail messages, spamming unlicensed pharmaceuticals, stock scams and other from around 45,000 malware-infected zombie PCs