I guess you know that computer viruses are everywhere. This guide will help you and your computer avoid being infected by viruses. There are many ways to help you prevent being infected by viruses having a good and an updated anti-virus will not always save you but it is one of the best way to prevent it.
Types of viruses
There are lots of types of viruses most of them are simply programs or scripts that will cause various problems or damage to your computer such as corrupted files, creating a copy of itself, deleting your hard rive files etc. Most of the viruses spreads itself by mailing themselves to people on your address book and some of them will try to convince you to open the attachment, But that trick never worked on me. In fact, I found myself emailing people just to make sure they really did send me something. It does not hurt to be safe.
Worms are different kind of virus but the same idea. Worms are designed to copy themselves a lot on a network and they usually eats up bandwidth by sending commands to servers to be able to get in. When the worm successfully infiltrate the system it will try and go into other servers from there. Some worms such as the SQL slammer will simply send themselves over and over so many times that they will clog up networks, and sometimes all of the internet. Worms usually affect servers more than home users, but again, this depends on what worm it is. It is suspected that most worms are efforts from the RIAA to try to stop piracy, so they try to clog up networks that could contain files. Unfortunately, the RIAA have the authority to do these damages and even if caught, nothing can be done.
This type of virus is simply like a server that hackers use to get into the computer. An example of this is Subseven, it can enable a hacker to do various things such as control the mouse, eject the cd-rom drive, delete/download/upload files and much more.
Boot Sector viruses are similar to file viruses but they go into the boot sector. These type of virus is hard to remove and can cause serious damage when the computer is booted, some of it’s kind can easily erase all the data on your PC just by booting your computer.
Most viruses have different characteristics. For example, a worm can also be a trojan and also infect the boot sector. It all depends on how the virus is written and what it is designed to do. That’s why there are not really strong structured categories, as they can easily mix one in the other.
Know the potentially dangerous files
Just like any other files, viruses must be opened before they can do damage. Most of them comes from e-mail attachments. Most of this type disguise as someone you know and convince you to open the attachment. My great advice: Never open attachments at any cost! Some viruses will infect files in programs, so opening a program will actually open the virus, maybe the same one, or another part of it.
All files have what is called an extension; This is the 3 last letters after the last period. For example, setup.exe has a file extension of .exe.
Extensions to watch out for are .exe .com .bat .scr .pif .vbs and others, but these are the most seen. .exe .com .bat .pif and .scr are valid extensions for executables. A virus writer will simply rename it to one of these and it will work the same way. .pif is a shortcut to an ms-dos program and will have the ms dos icon, but will still execute whatever code is in it, so an .exe can be renamed to .pif and be run the same way. .bat is a batch file, which can contain instructions to do various file activities, but again, a .exe can be renamed to .bat and it will execute it! .vbs is a visual basic script. For some reason, Microsoft provides this scripting language along with the scripting host to make it more convenient to design and write viruses quickly and easily, I’ve never seen another use for this scripting language other than for writing viruses. There are programs that are written with that language, but it is compiled into an exe. Exe is the usual extension for programs, you would not have a software CD install a bunch of vbs files all over!
Bottom line is, if you don’t know what a file is just don’t open it. Some viruses will sometimes be named a way as to mask the real file extension to make it look like a harmless file such as a image file. This is easily noticed, but can still be missed. Simply don’t open unexpected files.
If you get something that appears like something legit, just ask the person it came from if they sent it. Most viruses use a friend’s address to make it look like it comes from them. The virus does this by using the person’s address when sending itself to the address book contacts.
Email is not the only source of viruses you can also get viruses from P2P file sharing programs such as Kazaa, Bearshare, Limewire, direct connect etc.
Watch out for the size when you are downloading programs. When you see a program that you expect to be rather large such as game don’t download it, don’t get files that is 10KB it is more like to be a virus than a legit file. File size is not the only thing to watch I’ve been caught with a virus even with large files, as an exe is still valid even if junk is added at the end, so a 64KB virus will still function even if it is turned into 650MB.
You should look for icons, fortunately, virus writers don’t take time to put icons. If you are downloading a setup file your setup file should have setup icon if it’s blank that file is more or less a corrupted file or a virus.
Best advice after downloading and before opening a file is to scan it with an updated antivirus. but rely on your antivirus as we all know virus scanners are not perfect, if the virus has not been reported to them yet, they won’t know to create a definition for it!
Changing settings to stay safe
If you happen to open a virus and you want to avoid the virus from infecting your friends the simplest to do is not to use the windows address book. It’s very easy for viruses to get through windows address book and unfortunately Microsoft is not doing anything to fix it. Just put them in a spreadsheet or even better write them down somewhere. Don’t use the address book!
Avoid using the auto preview some viruses can open themselves just by opening the mail. There are security holes in Microsoft mail programs that allow this. To disable auto preview on Microsoft outlook just click on the menu and remove auto preview. remember to do this for every folder but the inbox is most important. In Outlook Express, click on the view menu and go to layout. In the dialog box, you will see a check box for show preview pane. Uncheck it and click ok.
Removing a virus
Sometimes a clean install wont remove viruses the best way is perform a low level format. This is especially true of you got a boot sector virus, as even repartitioning and formatting won’t quite remove it, but sometimes you can get away with an fdisk /mbr, but not all the time. Use good virus removal tools but then again clean install is always the best way to ensure that it’s gone for good.
Viruses are out there, don’t be one of the many infected ones! Stay alert and stay safe! Don’t open unexpected files, regularly update your virus definitions and scan downloaded files!
I hope this article was useful for you!