Microsoft filed five civil lawsuits against companies allegedly using online advertising to serve malware. The lawsuits allege individuals using the business names Soft Solutions, Direct Ad and ote2008.info used malvertisements to distribute malicious software or present deceptive websites that peddled scareware to unsuspecting Internet users. Malvertising works by camouflaging malicious code as harmless online advertisements, which then lead to harmful or deceptive content. Microsoft: “We are filing these cases to help uncover the people responsible and prevent them from continuing their exploits”””
Source: https://threatpost.com/microsoft-takes-aim-malvertising-threat-092309/72218/