A computer virus is a program that has been designed to copy itself, spreading from one file to another and causing varying degrees of disruption to your computer. The definition of virus is down to its ability to replicate, not to the extent of the problems that it causes. Some viruses do nothing more sinister than making your keyboard bleep or display a message. Conversely, even if a program adversely affects your computer, that doesn't necessarily make it a virus, unless it replicates itself. Having made this point, it must be remembered that all viruses are bad news if for no other reason than that they will inevitably be passed on to someone else's files, which will probably upset them and thus cause no end of grief for CCSG. Two common types of problem virus are Macro Viruses (which infect data files such as those in Microsoft Office) and Boot Sector Viruses (which infect floppy disks and the boot sector of hard disks.)
A worm is a self-replicating virus that is capable of duplicating itself by using parts of an operating system that are automatic and invisible to the user. A worm will spread much more quickly from computer to computer, particularly across a local network. Examples of worms include the much publicised Nimda and Sircam.
What isn't a virus?
Many people rush to the mistaken conclusion that just because their computer isn't behaving the way that they expect it to, then there must be a virus lurking about somewhere. This isn't necessarily the case.
How do viruses and worms spread?
It used to be true to say that a computer virus could not spread from computer to computer without assistance from users. However, some "popular" applications such as certain e-mail clients will now preview files without user intervention and will thus execute an infected file. Also, Worms are capable of infecting directories on network shares and spreading whenever somebody tries to open certain documents on these shares. The other possible ways in which viruses can spread are via:
Fortunately, with a little bit of care and vigilance, it is possible to virtually eliminate the spread of viruses, by following the procedures outlined below.
Virus Prevention (What YOU must do)
All the PCs on the network have anti-virus software installed,
currently Trend Antivirus.
If you come across a machine which does not then please contact CCSG.
The virus definition databases are updated each time a new virus has
been identified so the anti-virus software should always be capable of
detecting all viruses, including the very latest. The machines have
been configured to scan all local hard drives automatically on a daily
basis, so normally you need not worry about doing this yourself. There
are however, four important areas for which YOU must take
Below are links to good sites you might want to visit to determine if a virus warning you have received is a hoax:
Other links to useful sites, including overviews, tutorials and breaking news: