A computer worm is different than a computer virus. Yes, they are both self-replicating, but a computer virus is not always self-contained. This means that a computer virus can sneak into other system files and keep spreading and infecting files within that targeted computer; a virus depends on other files to spread. On the other hand, a computer worm likes to work alone; it does not need other files to spread and typically does not infect existing files on the computer. Viruses typically only harm the targeted computer, whereas worms infect the network. Worms consume bandwidth, which can cause havoc on accessibility if a large enough spread throughout the network occurs. According to Microsoft, some worms clog networks, making it impossible to view certain web pages and possibly download programs, most commonly preventing the download of security products.
So, how then does a computer worm spread? Well, just as there are many different types of worms, each unique, there are a number of ways a worm can spread. Commonly, a computer worm spreads through the use of the Internet. Email is a big highway in which a PC worm spreads. A worm gets embedded into an email attachment. When the user opens the attachment, the floodgates of the spread open. These type of worms can gain access to your email address book and within seconds spread a clone of the worm to all recipients in your address book.
Another way these worms spread is through Internet chat programs. Programs such as Skype, MSN Messenger, Google Chat, IRQ, AOL Messenger, Yahoo Messenger are great carriers to house the worm and contribute to its spread. Other worms spread through network “sharing” type files. Worms have been known to spread through the use of music and movie file sharing sites such as the old MegaUpload and FileServe. Similarly, some uses have been infected by computer worms when downloading bit torrents.
How can you be safe from the dreaded computer worm? Don’t open emails or email attachments from unexpected senders. Don’t let curiosity get the better of you on that email that has a strange subject line. Become a fan of the “delete” key. Another great tip with regards to email and computer worms is to turn off the email preview page. When you have the preview page of your email turned on, the email automatically opens when you click on it once. You can click on the email subject line in your email list by mistake, and open up the email even though you didn’t intend to, so turn off the preview page.
Further, a good anti-virus program is a must. But because the new worms are continuously being updated, you must be diligent in updating your anti-virus program database regularly, if it isn’t done automatically. Install operating security patch updates immediately to further protect your system. Lastly, make sure your firewall is turned on.