What is a Virus?
One of the things that worries new users of the internet is the risk of getting a computer virus. Newspapers often indulge in scare stories of how the newest virus will bring everything grinding to a halt.
A simple virus will corrupt programs and files. It could end up destroying all the information on your computer. A worm will spread to other computers, often by sending itself to all the addresses in someone's Address Book. A trojan will hide and let you download it when you download something else. Then it will perform some sort of unwanted action.
How do you get a virus?
Virus come into your computer from an outside source. They could be sent to you in an email, downloaded from the internet or transfered to your computer on a floppy disk.
Should I pass on this virus warning?
It is quite common to receive a panicky email which has been passed on to you from a friend. It will warn of some new virus, often claiming that the warning originally came from Microsoft itself. The message asks you to forward the email to everybody you know.
Well, don't. The message is almost certainly a hoax, although passed on to you in good faith. The only virus is the message itself spreading around the internet.
You can check out whether a warning is a hoax by visiting: Symantec's Hoax List.
Who has a virus really come from?
Often the infected email will not have come from the person it seems to have come from at all - someone else's computer may be infected and the virus has picked an email address at random and pretends the messages have come from that address. The virus is then sent to all the other addresses in the infected computer's address book!
There is a free on-line virus scan for your computer at: PC-cillin (Trend Micro).
You can download a free anti-virus program from: AVG AntiVirus.
How do you avoid getting viruses?
If you follow these few simple steps you should be able to avoid viruses from affecting your computer:
1. Virus detection:
You need to have some sort of virus protection on your computer (an anti-virus program). This will warn you if you have accessed a program with a virus. These should be updated frequently to be able to detect the newest versions of viruses.
2. Opening attachments:
Sometimes you will receive emails with files attached. Attachments can be very useful but be wary of them. If you know that someone is going to send you a photograph, a word document or a music file then it should be safe to open.
If an email with an attachment arrives from someone you do not know, then do not open it. It is best to delete it. If an attachment arrives unexpectedly from someone you know, then play safe by emailing them back and asking if they have just sent you a file. Only open it if they assure you they have.
A lot of viruses have been going around containing an attachment and a message like: "I send you this file for your opinion" or other plausible reasons why you should open the file. Delete them, even if they seem to come from someone you know.
3. Downloading files:
There may be times when you will want to download files from the internet. From time to time you might want to update to the latest versions of programs. But avoid doing this unless your computer has virus detection software
Be very wary of downloading "warez" and free copies of software you would normally have to pay for from dubious sites.
Reduce the risk of downloading viruses and trojans by only downloading files from reputable websites. These include software manufacturer's own sites and well-known download sites like Tucows, Download.com, Shareware.com and NoNags.
4. Sharing memory sticks, USB drives and floppy disks:
This has been a common way of passing on simple viruses. Swapping software may seem like a cheap way to acquire things until you get a virus that ruins your hard drive. You do not know how careful the other person has been or where the software came from.
Be careful when someone passes Word files on to you. Switch off Macros because they can contain viruses.
Protecting against Spyware
Spyware consists of cookies and other files that track you and let their originator know things about your internet activities. Some cookies are useful and perfectly harmless, such as those from online shops and other sites, that remember who you are next time you visit. Others, however, are more intrusive, and are only there with a view to your being targetted by, for example, a selling campaign.
Some forms of spyware can steal passwords or bank details, or cause lots of unwanted pop-up ads. An Anti-Spyware program can detect intrusive cookies along with other nasties and delete them.
You can also download a free Anti-Spyware program that runs in the background, such as: SpywareBlaster.
Installing a Firewall
A Firewall is an essential tool to use when going on the internet. It monitors activity and checks on files going into and out of your computer. It should prevent unwanted files from loading, and also stop external sources taking data (such as passwords, bank details, etc.) out of your computer.
Some broadband set-ups include a router which includes a hardware Firewall.
The built-in software Windows Firewall that XP and Vista computers already have does not successfully monitor all outgoing data from your computer, but there are several reliable free Firewalls that do.
Two popular free Firewall programs are: Comodo (recommended) and Zone Alarm. Only one software Firewall should be running on your computer. If you download one of these, make sure you turn the built-in Firewall off.