Microsoft has opened the doors of court, filing civil suits in a district court in Microsoft's home state of Washington, against five advertisers on Friday, in a bid to stop malicious online advertisements, more precisely 'malvertising'. These persons are allegedly posing a threat to internet security by injecting malicious code on web pages through advertisements.

These codes are capable of easily infecting the computers of the users with unwanted applications and programs. Microsoft, being unaware of actual identity of persons injecting such advertisements, has filed case against business names which are promoting such Ads. The move, as per Microsoft, may discourage growing problem of Malvertising in future.

Tim Cranton, Microsoft Associate General Counsel, wrote in his blog: "Microsoft works vigilantly, using both technology and the law, to fight illegal activity that undermines people's trust in the Internet and online services. Today's filings build on other recent actions we've taken against click fraud and instant messaging spam."

The firm has also advised people against malicious ads, urging them to use up-to-date security softwares; besides avoiding divulging personal information on suspected websites.