According to the company, the perpetrator has been using illegally acquired keys to activate copies of its software for the past three years.
The list of programs includes Windows 7 and 8, Office 2010, and Microsoft Server 2008 and 2012.
As part of a safeguard to ensure that customers obtain and use original products, Microsoft uses a 25-character product key for most of its software that users must have and enter during installation process.
Microsoft said that it's likely that these keys were stolen from its supply chain.
The illegal activities were tracked down coming from the same IP address belonging to a Comcast subscriber, who apparently has “contacted Microsoft activation servers over two thousand times between 2002 – 2015.”
Having exhausted the company's time and resources to make a clear identification of the copyright infringement suspect and failing to do so, Redmond is now asking the court to serve Comcast with a subpoena to reveal the identity of the individuals.
It remains to be seen how the country's biggest home internet service provider will react to Microsoft's request. Concurrently, a lawsuit has been filed in a Seattle federal court to bring the unnamed defendants to justice.