Microsoft is cracking down on scammers who call victims and tell them there is something wrong with their computer. They often propose to do the work for free.

Since May of this year, Microsoft has received over 65,000 customer complaints regarding fraudulent tech support scams. Microsoft issues a report that stated that over one-third of U.S. citizens fall for the scams once contacted. This results in approximately $1.5 billion in financial losses each year.

According to the complaint filed with the U.S. District Court for the Central District of California, Microsoft used a computer that its experts confirmed did not contain malware, viruses, or any other harmful computer files or programs.

When they contacted one of the scam companies, the representative claimed that the Windows file system modules were “corrupted due to the presence of polymorphic infections and other harmful viruses,” claiming to have found 75 issues of concern. The rep asked for $250 to fix the issue and once that was paid, asked for an additional $610 to “fine tune” the computer.

In some cases, scammers even installed malicious software, Microsoft said. It asked the court to issue a ban against the companies and award damages.

You can report such scams on a Microsoft website.