What kinds of files can spread viruses?
Viruses have the potential to infect any type of executable code, not just the files that are commonly called 'program files'. For example, some viruses infect executable code in the boot sector, or the section of a hard disk that contains operating system and file information. Another type of virus, known as a 'macro' virus, can infect word processing and spreadsheet documents that use macros. And it's possible for HTML documents containing JavaScript or other types of executable code to spread viruses or other malicious code.
How do viruses spread?
When you start a program that's infected by a virus, the virus code will also run and try to infect other programs, either on the same computer or on other computers connected to it over a network. And the newly infected programs will try to infect yet more programs.
When you share a copy of an infected file with other computer users, running that file may also infect their computers; and files from those computers may spread the infection to yet more computers.
Some viruses, known as 'multipartite' viruses, can attack both the boot sector and the executable files at the same time. This type of virus can keep re-infecting a system over and over again.
What do viruses do to computers?
Viruses are software programs, and they can do the same things as any other programs running on a computer. The actual effect of any particular virus depends on how it was programmed by the person who wrote the virus.
Some viruses are deliberately designed to damage files or interfere with your computer's operation, while others don't do anything but try to spread themselves around. But even the ones that just spread themselves are harmful, since they damage files and may cause other problems in the process of spreading.
Note that viruses can't do any damage to computer hardware. They won't melt down your CPU, burn out your hard drive, cause your monitor to explode, etc. Warnings about viruses that will physically destroy your computer are hoaxes, not legitimate virus warnings.
What is a Trojan Horse program?
Viruses are software programs, and they can do the same things as any other programs running on a computer. The actual effect of any particular virus depends on how it was programmed by the person who wrote the virus.
Some viruses are deliberately designed to damage files or interfere with your computer's operation, while others don't do anything but try to spread themselves around. But even the ones that just spread themselves are harmful, since they damage files and may cause other problems in the process of spreading.
Note that viruses can't do any damage to computer hardware. They won't melt down your CPU, burn out your hard drive, cause your monitor to explode, etc. Warnings about viruses that will physically destroy your computer are hoaxes, not legitimate virus warnings.
What's the story on viruses and Email?
You can't get a virus just by reading a plain-text Email message. What you have to watch out for are messages that contain embedded executable code (i.e. JavaScript in an HTML message) or messages that include an executable file attachment (i.e. an encoded program file or a Word document containing macros).
In order to activate a virus or Trojan horse program, your computer has to execute some type of code (run the program). This could be a program attached to an Email, a Word document you downloaded from the Internet, or something received on a disk. There's no special hazard in files attached to e-mail messages: they're no more or less dangerous than any other file.
1USA customers are better protected from viruses, malware, spyware, rootkits and other types of bad programs -- because 1USA runs FOUR different anti-virus programs on each incoming email... plus, if you have the Sender Verification system turned on on your account, there is NO chance of someone pushing infected files via email.
You DO need to be watchful what LINKS to click on - either while surfing the web or links that arrive in an email. But again, since only known senders get past the Sender Verification system, there is an 85% chance that you can depend that your friend won't email you a link to an infected website. This is where your Internet Security software picks-up and protects your computer 99% of the time.
1USA Recommends Trend Micro Internet Security software. A.V.G. just doesn't do a compete job in recent years, unless you buy the $50/yr version.
How do I deal with a virus infection?
First, keep in mind, that just because your computer is acting strangely or one of your programs doesn't work right, does NOT mean that your computer has a virus.
- If you haven't used a good, up-to-date antivirus program on your computer, do that first. (If you're looking for a free antivirus program, try HouseCall.) Many problems blamed on viruses are actually caused by software configuration errors or other problems that have nothing to do with a virus.
- If you do get infected by a virus, follow the directions in your antivirus program for cleaning it. If you have backup copies of the infected files, use those to restore the files. Check the files you restore to make sure your backups weren't infected.
- For assistance, check the Web site and support services for your antivirus software.
Note: In general, drastic measures such as formatting your hard drive should be avoided. They are frequently useless at cleaning a virus infection, and may do more harm than good unless you're very knowledgeable about the effects of the particular virus you're dealing with.