There are a number of technically distinct types of malicious software that we tend to group together under the term "virus." The "true" computer virus infects files on the host computer and, as in nature, self-replicates, (creates copies of itself.) It may be destructive or it may just spread. Even "innocuous" viruses slow down computers and networks and cause degraded performance and crashes.
A Trojan Horse does not replicate itself but must be "invited" (usually
unwittingly,) by the user onto their computer. It may destroy data or steal
passwords. It may use the host PC to perform a Distributed Denial of Service
(DDOS) attack on another computer, or it may simply take up memory and
A Worm, like a virus, replicates itself between computers. Unlike a virus, it can do this without infecting "host" software. As with a virus, the effects of a worm can range from the catastrophically destructive to the rather annoying.
However, we will use "virus" as generic term for any such malicious code from now on.
Other unpleasant types of program that may find their way onto your computer are as follows:
Scumware is software that changes the content of websites you view. Advertisers pay the manufacturers of this software to "hijack" Internet traffic and send it to their web site. The topText browser add-on from Ezula.com is perhaps the most prevalent such application. It is distributed as part of the seemingly innocuous Kazaa file-sharing package. Microsoft's own "Smart Tags" have now been withdrawn after allegations that they also constituted Scumware.
Spyware or Adware are terms used to describe programs that display
uninvited advertising on your computer or track your actions and Internet use. They are usually disguised as useful applications to help persuade you to install them. The Gator Corporation is probably the market leader in this method of advertising. If you install one of their applications you'll soon notice advertising popping up all over your PC. Spyware also raises huge privacy concerns, as there is no way of the user knowing for sure quite how much information is being collected or how it is being handled. Whilst web sites publish privacy policies, the progress of effective enforcement methods is years behind the industry, so trust inevitably enters the equation. Many pro-privacy campaigners believe that even cookies - tiny information files stored on your computer by a website which may be used to select what advertising to display to you on a return visit, or even to store personal data - represent a threat to online privacy.
Unfortunately the argument is not clear-cut as cookies also provide a number of real benefits - with cookies switched off, for example, you would have to log in to every familiar web site such as Hotmail.com or Amazon.corn on every visit.
Genuinely malicious, but thankfully less prevalent, forms of spyware can also
be used to log "key strokes" and steal information such as passwords from
Pop-ups are not in themselves harmful, but tend to annoy or even enrage web surfers! In extreme cases, a "chain" of pop-ups can open so quickly that they crash your computer. Often, attempting to close a popup will only spawn three more. Many spyware applications also attempt to install themselves through pop-ups.
Diallers used to be the darlings of the online Adult industry. A surfer was offered "free" adult material to download. They actually ended up downloading a piece of software that closed their normal Internet connection and redialled it using a premium rate 'phone number. These programs only affect computers with dial-up modems installed and connected. Unsuspecting users could run up phone bills of thousands of pounds as they paid two pounds a minute or more to access the Web, often for months after downloading the software. Most web surfers are wise to this ploy by now, though many of the less-scrupulous and seedy sites still try it on.
Spam is the sending of unwanted and unsolicited emails. Spam is the electronic world's biggest problem. While most countries are trying to enact laws to make the sending of such emails an offence, it remains big business primarily because some people will buy spam offers. The best way to deal with spam is to NOT reply but delete immediately, set your email software to not accept emails from people you don't know or set it to filter emails according to set words (sex, viagra, money etc.) Unfortunately a fool proof method of filtering out spam does not yet exist.
If you have a website you might also want to consider linking to this antispam page as it adds a page of false email addresses to the trail. Email collecting programs (spam bots) will be sent into an infinite loop by following the link at the bottom of the page and will get more and more fake email addresses stuck in their databases.
For the latest Viruses and Hoaxes, go here.
There are excellent free-of-charge anti-virus solutions available:
Grisoft's AVG Free Edition offers full anti-virus protection including email attachment scanning. To obtain the software you must fill out a registration form and wait to receive an activation code in your email. The software regularly wins awards in PC magazines for its quality and value. Some users have reported problems actually downloading the program however. It can be annoying to go through a long-winded registration process but then be unable to download the software at the end of it! No technical support is
provided for the free version of the software.
The AntiVir anti-virus software To obtain the software, simply click the "download" link on the left and then on the "AntiVir" graphic. You are not even required to register the software or to provide any personal information. Excellent free technical support is provided in the forum. Although the company is based in Germany, the forum is bilingual, and many users have reported that help is quick in coming and efficient. I personally recommend this software, having used it since an early version. It is fully featured, including a task scheduler and email attachment scanning! The name given to the actual scanner application ("Luke Filewalker",) still tickles me every time I see it!
It should be noted that both the free products mentioned above are licensed for personal use only.
In addition to these free downloadable virus scanners, there are also a number of websites which offer free online virus scanning over the Internet.
The Panda Active Scan:
This is an excellent scan which is guaranteed to be fresh as the virus database is updated daily. You have to give an email address but can easily unsubscribe from the company's occasional mails if you wish, (though they are actually a useful source of genuine early warning virus alerts.)
The Trend Micro Housecall:
This online scanner is a demonstration of Trend's corporate distributed scanning technology. It is no less useful for it, though it takes some time to download initially.
A firewall can be a piece of software or a dedicated hardware/software
combination. Firewalls are designed to plug the security risks associated with open ports. They do this by:
Most firewalls allow a degree of customisation so that you can, for example, tell your firewall to always allow data to flow to and from regularly used applications such as Internet Explorer.
A software firewall sits on your computer and polices your computer's
communications with the world outside. Whilst a software firewall is adequate for most home users, it can only be as secure as the Operating System it runs on. Hardware Firewalls are also available and are considered more secure.
The most popular Windows firewall is ZoneAlarm.
Whilst the free version does not offer quite as many features as the Plus and Pro versions, it's free-of-charge and quite sufficient for most users, especially when used in conjunction with one of the free virus scanners mentioned above.
Removing some adware may prevent your file-sharing programs from working.
A Spyware removal tool should be used to complement a Virus Scanner and a
Firewall - it replaces neither but adds an extra level of security to your PC.
There are also a number of genuinely free Spyware removal tools available:
Lavasoft's Adaware free edition:
It is fully featured, the main differences between the free and paid ("Plus") edition is that it includes neither popup stopper nor a scheduler (remember to run it yourself!)
Probably the best spyware elimination software on the market (it recognizes far more rogue programs even than the market-leading adware programs).
it is "donationware", and even if you choose to give a voluntary donation to the author, it is still truly excellent value.
The Alexa Toolbar for Microsoft Internet Explorer comes with a popup stopper
The irony with this solution is that every time a website tries to popup a new
window, the Alexa toolbar gives you a little popup message saying "abc website is trying to launch a popup, do you want to let it?" This is not quite as ridiculous as it sounds, however, as you only get this message once per site.
The Google Toolbar comes with an Auto-fill feature (allowing you to store details like your name and email address to add them quickly to a web form,) and also allows you to search the web directly from the toolbar.
Information supplied by DOT-COMmunications
Calderdale's primary Not-for-Profit computer support organisation