|
Security on the Internet / Computer viruses
Definition
What not to do
Virus Alert
Anti-virus software
In summary
Definition
A computer virus is a program that looks for other programs in which it can secretely introduce its own instructions. This process, called infection, is the principal characteristic of a virus: it reproduces itself by modifying other programs. When infected programs are executed, they seek for other programs to infect, creating a propagation effect.
This typical function of reproduction usually comes in pair with another one, which varies according to each virus. It can be anything : display a message, erase files, open a breach for intruders in your system, format your hard disk, etc. The virus can wait for a pre-set moment or a particular event to enter into action, or, in least malicious cases, simply never do a thing.
What not to do
To guard against Trojan horses and viruses, certain common errors must be avoided. First and foremost, never execute programs which do not originate from an entirely reliable source. Reliable to mean trustworthy companies, organisations or sites that are well known and of sound reputation. All recognized sites have an alphabetical address respecting the format name.network.domain. for example: www.canoe.com or ftp.videotron.com. A registered domain name is not a security warrantee, but a strictly numerical address (similar to 10.149.67.205) that cannot be associated with any alphabetical address would have all the appearances of a little known site. It could very well be a site for hackers. Servers with contents bordering on illegality or indecency should also be avoided. At least, do not accept program files from them that can be executed on your system.
Do not accept programs transferred on IRC, ICQ or via other types of on-line chat rooms, even if they are sent by a friend. Lets pretend that you are chatting with a friend you trust entirely. He himself knows a friend, who knows another friend, and so on. Could you trust a friend of a friend of a friend of a friend of your friend? Even if you were convinced of the good faith of all these people, the answer to the question should be NO because you do not know their level of exposure to risk, nor the security measure they apply to their system.
You must apply similar precautions to electronic mail, diskettes, and to self-copied compact disks (CD-ROM)), i.e. copied by a user rather than pre-recorded by a manufacturer. Unless you know their utility, unless you are sure of their source and are convinced that the sender applies reliable security measures, do not accept such disks and destroy program files attached to e-mails. If you have no other choice but to accept them, detach them and scan them with the lastest update of your anti-virus software prior to executing them.
Virus alert
From time to time, virus alerts are communicated and retransmitted by electronic mail or on Usenet forums (newsgroups). Unfortunately, a number of them are false alarms. These dirty tricks are hoaxes exploiting the good faith of people who send the message. It is advisable not to publicise any virus alert prior to preliminary verification in order to avoid electronic mail and news forums spamming. In other words, not to cry "Wolf !" when there is no wolf. Each time a false alarm is launched, net surfers are bound to give less credibility to future alarms which may perhaps be serious alarms.
Before launching a virus alarm, verify its validity by asking a recognized anti-virus center to corroborate the existence of the virus. If you doubt that an alarm is founded or if you require more information on a virus in particular, several data bases are constantly kept up to date. They include a description of recently discovered viruses and of those which have been long identified, as well as a list of most hoaxes.
Anti-virus software
A great number of tools exist to guard against viruses. Anti-virus software can detect or desinfect numerous viruses, but new still unknown stocks frequently appear. This is why it is important to regularly update your software's list of viruses. Usually, manufacturers offer this free service with the purchase of their product.
Anti-virus software are an additional security measure and not a subsitute for the basic measures mentioned above. These tools should be considered as insurance policies or remedies against evil and should always be used in conjonction with basic preventive measures.
Following are a few useful links which offer resources for protection, verification of systems' integrity, disinfection , if need be, or to simply acquire more knowledge on viruses:
McAfee Anti-Virus
Dr. Solomon
Norton AntiVirus
Free On-line Dictionary of Computing (FOLDOC), Virus section
In summary :
-
Never execute programs unless they are sent by an entirely reliable source (i.e. companies,
organisations or reliable sites that are well known and have a reputation to maintain)..
-
Do not execute programs sent by another user via electronic mail or via chat rooms such as IRC or ICQ unless
it is absolutely necessary, and only after a scan with the latest update of your anti-virus software.
-
Do not accept diskettes or self-copied compact disks (i.e. copied by a user rather than pre-recorded by a manufacturer)
without scanning them with the lastest update of your anti-virus software prior to executing them.
-
Do not retransmit virus alerts without prior authentication by a well-known anti-virus center.
-
Update the description lists of your anti-virus software on a regular basis.
|
