Windows 7: College hit by viruses for 10 years.

Summary: At the City College of San Francisco, viruses have reportedly harvested personal student data for over a decade.
At the City College of San Francisco, an infestation of viruses has reportedly harvested data for over a decade undetected.
One of the college’s computer labs was immediately shut down by the CTO David Hotchkiss after one of the viruses was discovered. The virus in question has led to fingers being pointed at China and Russia, due to the transmission of user data mainly being sent to these respective countries for an estimated decade. Data has also been sent to other countries including Iran and the U.S itself.
Decade old virus harvests information from college computers | ZDNet