The person behind the virus can access information from the victim's computer or even use the infected computer to commit crimes. In computing terms, this is a system-level compromise, and it's bad news for the computer's owner. That's because the worm creates a backdoor into the computer's operating system, allowing a remote user to access and control the machine.
It's called spoofing - the e-mail appears to come from one source when it's really coming from somewhere else.Ī Windows 2000 machine infected by the Code Red II worm no longer obeys the owner. But it could also take another name from the contact list and place that address in the "From" field in the e-mail client.
Like other viruses, it could comb through a victim's address book and send itself to contacts. Shortly after it appeared on the Internet, hackers modified the Klez virus in a way that made it far more effective.
It could even disable virus-scanning software and pose as a virus-removal tool. Depending on the version, the Klez virus could act like a normal computer virus, a worm or a Trojan horse. Some variations of the Klez virus carried other harmful programs that could render a victim's computer inoperable. The basic Klez worm infected a victim's computer through an e-mail message, replicated itself and then sent itself to people in the victim's address book. It debuted in late 2001, and variations of the virus plagued the Internet for several months. The Klez virus marked a new direction for computer viruse s, setting the bar high for those that would follow. Now that the love fest is over, let's take a look at one of the most widespread viruses to hit the Web. According to some estimates, the ILOVEYOU virus caused $10 billion in damages. Citing a lack of evidence, the Filipino authorities dropped the charges against de Guzman, who would neither confirm nor deny his responsibility for the virus. Filipino authorities investigated de Guzman on charges of theft - at the time the Philippines had no computer espionage or sabotage laws. Who created the ILOVEYOU virus? Some think it was Onel de Guzman of the Philippines. Rather than fix bugs, this program was a password-stealing application that e-mailed secret information to the hacker's e-mail address.
It wasn't until modems became common that virus transmission became a real problem. A hacker would save the virus to disks and then distribute the disks to other people.
In the good old days (i.e., the early 1980s), viruses depended on humans to do the hard work of spreading the virus to other computers. A doctoral student named Fred Cohen was the first to describe self-replicating programs designed to modify computers as viruses. While some pranksters created virus-like programs for large computer systems, it was really the introduction of the personal computer that brought computer viruses to the public's attention. But it took a few decades before programmers known as hackers began to build computer viruses.
The computer industry wasn't even a decade old, and already someone had figured out how to throw a monkey wrench into the figurative gears. In fact, in 1949, a scientist named John von Neumann theorized that a self-replicated program was possible. Computer viruses are just one kind of online threat, but they're arguably the best known of the bunch.Ĭomputer viruses have been around for many years. But the concern is understandable - according to Consumer Reports, computer viruses helped contribute to $8.5 billion in consumer losses in 2008. If you've never had a machine fall victim to a computer virus, you may wonder what the fuss is about. Some can wipe out the information on a hard drive, tie up traffic on a computer network for hours, turn an innocent machine into a zombie and replicate and send themselves to other computers.