What are computer viruses? Where do they come from? What damage can they cause? We explain what malware, Trojans, and worms are, plus which Internet security and anti-virus software you’ll need to protect computers against cyber attacks.
What Is A Computer Virus?
Computer viruses are software programs designed to infect computers and mess around with their operations, without the owner knowing. Viruses can corrupt or delete data, or even erase the hard disk.
- Viruses are hidden in illegal software, spread through downloads on the Internet or carried on removable sources, like CDs or USB drives
- Viruses spread when the software or document they are attached to is transferred from one computer to another – e.g. by attachments in infected e-mail messages
What Is “Malware”?
The term “computer virus” is often – and incorrectly – used to include all “malicious software”. In fact, a computer virus is simply a type of malware. Aside from computer viruses, other forms of malware include the following:
- Worm: A program that enters a computer network through holes in its security. It then replicates itself and sends copies to other computers in the network. Unlike a virus, it can travel by itself and doesn’t need to attach to an existing program.
- Trojan: A program that tricks you into opening an e-mail attachment or downloading a file from the Internet. Once activated, the damage may be minor (pop-up windows) or serious (deleted files, stolen data or activation of other malware). Trojan horses can’t replicate automatically, but they can create access to the system for attackers.
- Internet Bot: Software that runs simple and repetitive automated tasks over the Internet much quicker than a human can. A malicious bot secretly infects your computer and connects back to a central server where attackers can then gather private information, send spam, and open back-doors on your computer.
- Botnet: A group of computers used to run the automatic “bots” simultaneously. Infected computers are sometimes used as a part of a large botnets to carry out malicious attacks on high security sites.
- Spyware: Software that’s installed on your computer to collect personal information without your knowledge. This is then accessed by advertisers or other interested parties. Spyware can also interfere with control of your computer by changing its settings, slowing connection speed and losing Internet connectivity altogether.
- Spam: Unsolicited bulk messages sent randomly, most commonly via email
What Is “Phishing”?
Phishing is e-mail fraud where seemingly legitimate emails, are sent to scam you. The e-mails direct you to fake websites – claiming to come from trustworthy sources – where you’re asked to update information, such as passwords, bank account and credit card details.
What Are Networking Attacks?
Computer network attacks disrupt or destroy the information within your computer and networks. During “passive” attacks, information is monitored; during “active” attacks, information is altered to damage the data or the network.
Where Do Computer Viruses And Other Malware Come From?
A computer virus – and malware, in general – may be created to simply be annoying, bombarding you with spam and bogus advertisements. However, more commonly, viruses are created by cyber-criminals to steal your personal data, including passwords and credit card details, or to use your Internet connection illegally, without your knowledge.
How Do I Secure My Computer From Viruses And Other Malware?
To avoid viruses, it’s important that your computer has the latest security updates and anti-virus tools, you stay informed about recent threats, and follow a few basic rules when surfing the Internet, downloading files and opening attachments:
- Make sure that your computer’s operating system is up-to-date by regularly applying the most recent patches and fixes
- Install anti-virus software, which will find and remove viruses and other malware. Download updates frequently so that your software has the latest fixes, and make sure your anti-virus program can scan e-mail and files as they are downloaded from the Internet
- Install a firewall, which is a software system designed to monitor all traffic to and from your computer, blocking unauthorised access to a private computer network
- Anti-spam software filters the spam before it actually arrives in your e-mail inbox. Most Internet service providers (ISPs) or e-mail providers (such as Hotmail) already offer spam filtering, but it’s helpful to install anti-spam software on your personal computer
- Use a password on your computer and change it regularly to make it hard for others to access information. Passwords aren’t absolutely unbreakable, but they can put off unauthorised people from using your computer
A Few More Simple Security Tips To Protect Your Computer…
- Don’t open email attachments from people you don’t know
- Don’t leave your computer unattended when logged into your bank account or when you’ve provided credit card information on a shopping site
- Valid sites that use encryption to securely transfer sensitive information show an icon of a padlock on the bottom right of your browser window
- Enable Macro Virus Protection in all Microsoft applications and never run macros in a document unless you know what they do