Researchers have long thought that computer viruses behave much like biological viruses: they strike quickly and "virulently" and just as quickly disappear. Recent research by ICTP staff associate Alessandro Vespignani and Romualdo Pastor-Satorras of the Polytechnic University of Catalonia in Barcelona, Spain, based on an analysis of more than 800 computer viruses, suggests otherwise. In fact, their research indicates that computer viruses often continue to live for two or three years after they first appear and easily become endemic to computer networks despite the use of antiviruses. Vespignani and Pastor-Satorras' findings, which could lead to better and faster ways to protect our computers, will be published this week in Physical Review Letters. The intriguing insight has already received broad news coverage in USA Today, Nature and New Scientist.