Microsoft is going to court in a bid to crack down on malicious online advertisements.

The company announced on Friday that it had filed civil suits against five advertisers accused of injecting advertisements with malicious code on web pages.

Known as 'malvertising', the process is often used to infect legitimate pages with code that can cause users to become infected with unwanted or malicious applications.

The suits have been filed in a district court in Microsoft's home state of Washington. Because Microsoft does not know the names of the individuals actually placing the ads, the company is targeting the business names that were used to purchase the advertisements.

Microsoft has often used lawsuits and legal actions as a way to discourage illegal activity. The company has a history of using the courts to shut down individuals and companies who engage in activities such as software piracy.

Now, Microsoft hopes that the efforts will prevent others from attempting to profit from malvertising.

"Microsoft works vigilantly, using both technology and the law, to fight illegal activity that undermines people’s trust in the internet and online services," wrote Microsoft associate general counsel Tim Cranton in a blog posting.

"Today's filings build on other recent actions we've taken against click fraud and instant messaging spam."

Additionally, the company is advising users to avoid falling victim to malicious ads by using best practices such as using up-to-date security software and not giving out personal information to untrusted sites.