Scare raisers

摘要

One day in March 2008, Kent Woerner got a disturbing phone call from a teacher at an elementary school in Beloit, Kansas. An 11-year-old student had triggered a security scan on a computer she was using, revealing that the machine contained pornographic images. Worse still, the images had appeared on-screen as the scan took place.rnWoerner, who manages the computer systems for the local school district, jumped in his car and drove to the school. Repeating the scan, he too saw the images, alongside warnings that the machine was infected with viruses and spyware that were surreptitiously monitoring the computer's users. Yet a search of the hard drive revealed nothing untoward.