Sleepless in Cyberland – yes, that’s what viruses make you. Computer viruses are no different from biological viruses in the way they multiply in number and in the way they need a host to survive. However, in both scenarios, there is a cause — such as a weak immune system, an expired anti-virus software, or a malicious attack on your PC — for the virus to penetrate and multiply. Also, just as a biological virus spreads by injecting its DNA into a host cell, a computer virus attaches itself to a document or programme to infect other computers and programmes.

There are many different types of viruses, each programmed to infiltrate your computer and act in a variety of ways. Some are benign, while others are deadly. Due to an extremely large pool of viruses, it can be overwhelming at times to diagnose the type of virus and the root cause of the attack. The three most common viruses you are likely to encounter are:

Trojan Horses: This virus gets its name from the famous Greek epic, The Iliad. Similar to the events in the epic, a Trojan horse appears to be nothing more than an interesting computer programme or file, which the user downloads without any hesitation. Once the virus is in your computer, all hell breaks loose. Contrary to most viruses, a Trojan Horse doesn’t multiply but makes your computer susceptible to malicious intruders by allowing them to access and read your information. This is an extremely precarious situation for your personal privacy. Therefore, you should avoid downloading programmes or files from sites if you’re not completely sure of what the file or programme does.

Worms: A worm is a programme that replicates itself by using computer networks and security flaws. More complex than Trojan Horses, worms usually attack multi-user systems and spread over networks via emails. Once multiplied, worms scan the network and find more loopholes to exploit and attack. A classic example of a worm is the infamous I-LOVE-YOU virus. The key is to protect yourself from worms by updating your security patches and never opening emails from unknown senders.

Email Viruses: As evident by the name, these viruses spread through emails. An email virus automatically forwards itself to thousands of email addresses, waiting for the recipient to click them open. To avoid virus-infested emails, make sure your anti-virus is up-to-date and open attachments only after you are assured that they are from someone you trust. In addition, install a spam filter and a spam blocker.