The Most Destructive Viruses of All Time

With the SQL Slammer virus, more than 500,000 servers worldwide were infected, there was a general slowdown all over the Internet, and many corporations took their systems offline altogether. South Korea was hit so badly that much of the nation’s fixed-line and mobile Internet users were unable to access Web sites for about 12 hours. Hackers and security vendors are engaged in a never-ending game of leapfrog, with the former constantly devising clever viruses and the latter feverishly trying to concoct antidotes. As a result, through the years hundreds of thousands of malignant programs have infected networks around the world. Most have had minimal impact, but a handful have caused hundreds of millions — even billions — of dollars in damage. Some might mistakenly think viruses are a recent problem, but they have been around for at least 20 years. “Viruses have been around since the early 1980s, and their basic design hasn’t changed much since then,” noted Fred Cohen, a principal analyst with the Burton Group. In 1980s, one of the first viruses spread by infecting IBM (NYSE: IBM) mainframe systems. But the attack did not gain much notice because it did not infect many systems. At the time, mainframes were found only in large corporations, and many had appropriate security checks in place. Full Story