FITS - Preventative Maintenance

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A virus is a program or piece of code loaded onto your computer without your knowledge that runs against your wishes. Viruses can replicate themselves. All computer viruses are manmade.

Types of virus and virus-like programs

A virus is a manmade program or piece of code that causes an unexpected, usually negative, event. Viruses are often disguised games or images with clever marketing titles. Even a simple virus is dangerous because it can quickly use all available memory and bring your system to a halt. An even more dangerous type of virus is one capable of bypassing security systems to transmit itself across networks.

Computer worms are viruses that reside in the active memory of a computer and duplicate themselves. They may send copies of themselves to other computers through email or Internet relay chat (IRC). A worm is a special type of virus that can replicate itself and use memory, but it cannot attach itself to other programs.

Trojan horses
A Trojan horse program is a malicious program that pretends to be a benign application but which purposely does something the user does not expect. Although not a true virus, since it does not replicate, a Trojan horse can be just as destructive as a virus.

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The widespread adoption of email through the years has been accompanied by the development of malicious code - that is, email viruses and attacks. Email has provided hackers and crackers with an easy way to distribute harmful content to internal networks. School networks have been breached by worms and viruses, as well as by crackers, through the use of email. Hackers can easily breach the protection offered by a firewall by tunnelling through the email protocol.A typical firewall cannot protect against such email attacks, because it does not analyse email and its contents.

Because email messages can include file attachments, hackers can send infected files and hope that the recipient will open them, as happened with Melissa and Manwella. Yet other methods exist which allow a skilled and possibly malevolent hacker to inject code through email and run custom-made applications automatically while the end user reads the email text. Such problems have been around since the use of HTML in email and have been exploited by notorious worms such as the KaKworm, BubbleBoy and Nimda.

Methods used to attack your email system include:

Although most viruses gain access to your network via email, they may also be introduced via a floppy disk or CD-ROM containing a virus.

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A piece of antivirus software is a program that runs on a computer to detect and neutralise viruses and worms.

You can either run the software from time to time (typically at boot time) to detect viruses or leave it running continuously on the computer to provide a higher level of protection.

Because computers on a network are connected together, a virus on one workstation can easily spread around the network and cause serious damage.

The only prudent response to this risk is to prevent viruses getting onto your network in the first place. Antivirus software is the tool you need to combat this threat. Without antivirus software installed, your network is vulnerable to serious disruption and loss of data.

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There are several approaches to using antivirus software on school networks: access it online as required, load it on every workstation, install it only on key workstations and have it server based.

Antivirus software is not loaded on any workstation but is accessed online as required:

This solution may be suitable for schools on a very limited budget.

Antivirus software is loaded on each workstation on your network:

This solution is most suitable for smaller networks (fewer than 50 workstations).

Antivirus software is loaded on key workstations on your network:

This solution is only really suitable where limited workstations are used to access e- mail.

Antivirus software is loaded and controlled from a network server:

This solution is suitable for large or complex networks.

There are many suppliers of antivirus software for workstations and a more limited selection selling server- based solutions. Most packages are available on a trial basis. It would be worth trying several to see which is the most suitable for your school. In most cases it should be possible to negotiate a substantial reduction for an educational site licence. 

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Of all the applications on your network, the antivirus software is the most important to keep up to date.

New viruses appear almost daily and the ability of your network to resist attack will depend on the currency of the virus definition files. The antivirus software manufacturers update these files regularly to provide protection from the latest viruses. Purchase of most antivirus software includes a year’s free updates. Further updates usually involve extra cost.

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