Viruses and Hoaxes
Viruses and Similar AttacksViruses, worms, and Trojan horse attacks are common against personal computers. Many are now spread via email, perhaps as an attachment that contains a malevolent Word or Excel macro or an exe, vbs, or zip file for the user to run (and thus unwittingly run the virus code). Viruses can also be transmitted via instant messaging, file sharing programs, and malicious web sites that trick people into visiting them. A virus could also be contained in any file that is downloaded over the Internet or passed on a diskette, Zip disk, etc. from one computer to another. A virus is a small program that spreads itself by producing copies of itself. A virus typically infects a file or boot sector on a computer. Note that a computer virus replicates, somewhat like a virus infection in humans. These copies may be emailed to others, placed on the diskette in the floppy drive, etc. Viruses typically contain a payload: code that takes a specific action, sometimes on a certain date. The payload may instruct the computer to erase certain files, to display a message, to erase the flash BIOS (rendering the computer unbootable), to erase the entire hard drive, etc. A worm is like a virus in that it produces and spreads copies of itself, but does not infect a file (or boot sector). Often a worm requires some action by the user in order for the worm to spread itself. For example, by opening an email containing a worm you may allow the worm to send copies of itself to others in your address book. Some worms produce so many copies of themselves that they clog entire computer systems or tie up the networks between systems. A Trojan horse is what appears to be a useful program. However, there is a hidden payload. This payload may cause damage to the computer, give someone else access to your computer, etc. A Trojan horse does not usually replicate (produce copies of itself) automatically. Of course, attackers sometimes blend the features of viruses, worms, and Trojans to get a hybrid attack. Further Information on Viruses and Other Attacks
HoaxesMany of the messages popularly passed around on the Internet about viruses and other attacks are actually hoaxes. Unfortunately, many people believe these messages. One way to tell whether such a message is telling the truth is to check on sites such as those listed above to see if there is an official report from a reputable organization about such an attack. Don't just believe an email message from a friend that "company X has issued a warning about such and such an attack". Another method is to see if the message is a commonly know hoax discussed in one or more of the following Web sites: |
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