Virus protection software
A virus is a software program written by someone on a computer in a programming language and then sent across the Internet by email or spread by people sharing storage devices. They are sometimes designed to do nothing more than annoy (like making your keys beep each time you press one on your keyboard) but they often do a lot of damage such as wiping your hard drive clean or allowing your computer to be accessed by a hacker remotely or allowing a hacker to control your webcam!
You often hear people advising you not to open or double-click attachments sent with an email unless you are absolutely sure where the email came from. If you do, you might install a virus on your computer. If you are lucky, your computer will be set up to check all of your emails and any attachments you open, but a virus might still get through your computer's defences. Microsoft have identified the file extensions in the table to be a potential threat to your computer. A file extension consists of the three letters that you can see after each file name e.g. myHoliday.doc or NotVirus.exe . If you can't see the file extension in an email or in your file manager, then it is because that feature has been switched off and you need to switch it on. In Windows, you usually have to go to My Computer - Folder Options - on the View tab, remove the tick next to 'Hide file extensions for known file types' and then click on okay. It does vary between Windows operating systems but the process is similar for all of them.
There are all kinds of tricks that hackers use to try and get you to open an email attachment.
1. An email arrives telling you that your computer is infected with the latest virus in the news, and offers to remove it - all you have to do is click on the removal program attached! When you open the attachment, it disables your antivirus program and firewall. Then it installs a virus and reports to you that your computer is virus-free. The virus can then get to work.
2. Your friend sends you a file called greatGame.exe". You friends says they've played it and it's great so you open the attachment by double-clicking on it. The problem is, it contains a delayed action virus along with the game. You might get to play the game but now your computer has a virus. And all because you thought your friend knew what they were doing!
3. An email arrives that seems to come from Microsoft. The Microsoft heading and icons are correct and it looks real. The email tells you to patch your copy of Windows immediately as there is a security threat to your computer. The patch is attached to the message and as soon as you double-click it, you've disabled your firewall and anti-virus programs and installed a virus! It was a 'spoof' email, not from Microsoft.
4. Attackers can hide malicious attachments by using double extensions, e.g. "answers.txt.lnk" or "great_picture.gif.vbe". *.lnk, *.vbe and several other extensions are usually hidden. The file names you see are "answers.txt" or "great_picture.gif". When you double-click on them, you install a virus because .ink and .vbe can be used to do just that.
The above illustrates that the advice about never opening an attachment unless you really know where it came from and who sent it to you is very good advice!
The other main way of catching a virus is by sharing back-up devices like a pen drive. When you plug someone else's pen drive into your machine, if it has a virus, it could jump from their pen drive to your computer and infect your computer. When you plug a pen drive into your computer, the virus then jumps to it. If you take it to your friend's house, for example, and then plug it into their computer, the virus will jump to their computer, and so it spreads very quickly. Again, if you are lucky, your computer might stop the virus but on the other hand, it might not.
Anti-virus software is used to help protect your computer against viruses. It does this by checking potential viruses e.g. a file that you have double-clicked on from an email, against patterns of known viruses that it keeps in its database. If it finds a match, it quarantines the virus or deletes it and then tells you. As thousands of new viruses are written every week, it is important to ensure that virus patterns are kept up-to-date. This can usually be done automatically. There are free versions of anti-virus software and there are also many paid-for versions as well. These often come with many additional features and support if there is a problem.
Q1. What is a virus?
Q2. What is an email attachment?
Q3. What is a file extension?
Q4. Describe how a hacker can fool you into thinking that everest.jpg is a picture rather than a program that can install a virus on your computer.
Q5. Apart from emails, what is the other main way of infecting computers with a virus.
Q6. What is the best advice to avoid catching a virus by email?
Q7. What is the best advice to avoid catching a virus by sharing storage devices?
Q8. Use the Internet. Find an example of one free anti-virus program and one paid-for anti-virus program.
Q9. Why should you update your virus patterns in your database program regularly?
Q10. Why should you set your virus program to update its own virus patterns automatically?
Extension work
Use the Internet to research and make notes. Be able to explain what each of the following are:
a) Malware
b) Trojan horse
c) Firewall
d) Worm
e) Spyware