For more than two years, Microsoft's Digital Crimes Unit has been addressing customer complaints linked to a widespread telemarketing scheme, halted only recently by the Federal Trade Commission.

Microsoft was one of several companies that telemarketers claimed they were affiliated with to commit the scams.

Based primarily in India, the callers tricked customers into purchasing anti-virus services to remove non-existent malware from their computer. English-speaking consumers in the United States, Canada, Australia, Ireland, New Zealand and the U.K. were allegedly targeted, and other companies, like Dell, McAfee and Symantec, were mentioned in the ruse to convince customers of the calls' legitimacy.

“Microsoft was not made aware of the scams by the FTC,” Frank Torres, director of consumer affairs and senior policy counsel at Microsoft, told on Thursday in an email. “Rather, in 2010, Microsoft began receiving reports of scammers making phone calls to consumers pretending to represent a legitimate company, such as Microsoft or other companies, in an effort to trick [victims].”

On Wednesday, the FTC announced it froze the assets of numerous businesses that conned tens of thousands of consumers with their scams. The agency filed complaints against two companies in the United States, Finemaestros and Virtual PC Solutions, and India-based companies Pecon Software, Zeal IT Solutions, PCCare247 and Lakshmi Infosoul Services.

Six connected tech support scams were acknowledged by the FTC dating back to at least 2008. The complaint addressed 17 individual and 14 corporate defendants. An FTC news release on the case mentioned that Microsoft and other companies cooperated in the investigations.

Torres said Microsoft does not know how many customers fell for the racket.

In June, Microsoft released the findings of a survey related to the phone scams, which found that the average cost for victims was $875.