Computer Security & Hygeine
The Committee on Computers & Communications offers the following advice to computer users on matters relating to computer security and 'hygeine' - ie anti-virus measures. These note are intended for general computer users rather than experts and should be regarded as a starting point to keep your system safe and secure.
Develop a backup regime to suit your needs and stick to it!
There have been several cases within Presbytery of presbyters losing information which would have been safe if they had adopted a backup regime. You have been warned!
A backup regime will protect against data loss both in the event of malicious attack (by a virus or by a human thief), accident (eg fire) and hard-drive failure.
There are two aspects to consider: hardware and software
1. Make backups frequently: typically daily, although less frequently might be OK if you rarely add new files.
2. The traditional approach is to have two sets of backup media (disks) and to alternate using them, on each backup occasion over-writing the older of the two sets. This means that you always have two sets of backup data, one slightly 'fresher' than the other.
3. You probably only require to backup data files since in the case of loss you should have program files available for reinstallation. This makes the process of backup quicker and more efficient. Organise the folders on your system to make this easy (see below). Remember however if you are in the habit of obtaining software by download that it is effectively 'data' and also requires to be backed up.
4. Store at least one set of backups on a site away from the computer: this to guard against theft or fire loss.
In the 'old days' copying data files onto floppies was sufficient. With modern systems, file sizes are likely to be such that a simple floppy-based system is unlikely to be adequate. Some kind of auxiliary drive is a much more practical option.
Auxiliary hard drive:second hard drive might suit you, but be aware that it will not provide a backup if your whole machine is stolen, and it is not necessarily proof against a virus attack
Superfloppy': you may wish to consider a superfloppy drive which typically holds about 100MB of data. It is compatible with 'ordinary' floppy drives so you can use it in place of an ordinary floppy drive: this might be a suitable solution if you require to replace your floppy drive and it requires no 'expansion slots'.
Backup drive eg Zip drive: these have discs typically of 100 - 250MB. They may be fitted internally or externally as an add-on. External versions are probably nowadays easiest if they have a USB interface, although parallel (printer) port versions and ones with internal cards to go in the machine are also available. Some of these are supplied with software utilities to make your backup regime easier.
CD-RW Many modern machines are supplied with rewritable CD-ROM drives. These allow you to 'burn' your own CDs, and to overwrite old files, much like a floppy. The capacity of these discs is much larger than ZIP drives - typically 650MB. These are becoming very popular as backup devices and are particularly suited to approaches based on taking a 'drive image' (see below). This drive will also function as a conventional CD-ROM drive.
Windows-based machines are equipped with a backup program to help back backups of data. There are some points to note about their use:
1) backup files created with different versions of Windows are not always mutually compatible
2) they create a single 'compressed' backup file and it is not always easy to see how to extract a particular file from them
3) only later versions of Windows (Win 98 on ??) also have a scheduler which allows you to automatically schedule your backups (perhaps every night, for example)
You may prefer to buy or download a commercial backup utility which provides better or easier functionality.
My personal preference is to backup files either as straight copies of files or 'Zipped' using a Zip program such as WinZip: these make access easier than 'backup' files and can readily become archives rather than just backups.
A simple script or batch file (get a friendly nerd to write it for you!) which allows you simply to copy files onto your backup disk, rather than a sophisticated program, may well be sufficient to organise your backup regime.
Organise your hard drive. Mostly you will only require to backup data, not programs, so put all data files into a particular folder (eg My Documents). Then you only require to backup one folder.
Some people favour partitioning the hard drive, so that it looks to the computer like two separate drives; they use one partition for data and one for programs.
But be aware...
...Many programs by default put data files in another folder, such as their own program folder. If you can change this at installation (or later) do so, so that the files that program creates go into your data folder.
...What counts as important data to you? Your e-mails are probably an essential data file, though often overlooked. Where are they stored on your computer? If you can, make sure your e-mail files ( *.dbx if you use Outlook Express, *.pst if you use Outlook) are stored in your data folder or are otherwise included in your backup regime.
One approach to backups is periodically to create a drive image - that is a CD-ROM containing a compressed image of your entire hard drive. This makes restoration easy if you suffer hard-drive failure, a devastating virus attack or theft of your machine. It requires the purchase of a commercial software utility such as DriveImage. This approach would probably count as 'overkill' for the home-user, unless she were running a great many problems or had a particular setup which it would be crucial (or difficult) to recreate. This approach is best combined with partitioning the hard-drive into 'program' and 'data' partitions.
For our purposes a virus is any program which gets onto your system without your knowledge with malicious intent; it is also designed to propagate and spread to other systems. Worms and Trojans are similar types of such program. Not all viruses produce devastating effects (in spite of the scary messages, many of them hoaxes, which circulate by e-mail); however they are an annoyance and it is an important part of computer etiquette to ensure that your system is free of viruses, not only for your own sake but out of courtesy to anyone who may 'catch' one from you.
Virusses may be transmitted in two main ways:
By Disk
For the home user the original 'danger area' in virus transmission was via the exchange of floppy disks. Virusses can, in fact, be transmitted in any disk - including CD-ROMs. Much spreading of viruses has been done by people sharing software - which is often, in any case, against the licensing conditions of the software and so illegal. Cheap copy software of expensive programs bought at the 'Barras' is a sure way to get a virus. A virus transmitted in such a way may get into your computer simply by reading the disk. It is not safe to assume that 'genuine' manufacturers software is virus-free - Microsoft managed to spread a virus in its first issue of Office 95. However the risk of a virus from such a source is slight.
via the Internet
Potentially any kind of connection to the internet might permit malicious or unwanted activity on your system, although web-browsers such as Internet Explorer and Netscape Navigator provide security features to prevent this. Virusses get into your system by downloading files, but it is possible that even a simple e-mail will contain a hidden script which will download a virus-type program to your computer without your knowledge.
As with backups, you should adopt an anti-virus regime and stick to it.
1. Install a virus-checker
These can be bought 'shrink-wrapped' or downloaded from the internet and cost about £30.
eg Norton AntiVirus: http://www.Symantec.com
McAfee : http://www.mcAfee.com
A reliable virus-checker which is free for personal use, and can be obtained by downloading or from computer magazine cover disks is
Inoculate-IT: http://www.cai.com/products/inoculateit.htm
2. Configure your virus-checker
Do not assume that the default installation of the virus-checking program will provide all the functions you require.
Ensure it
i) checks the master boot record (MBR) on boot-up
ii) is capable of doing a complete system check on demand
iii) checks files being opened either automatically (this may slow down system performance and may be 'overkill') or on demand (eg to check downloaded files or disks obtained from a friend)
iv) Checks e-mail messages before they are opened to read and any attachments to the e-mail message (this mode of transmission of virus-type files is one of the easiest and most frequently encountered) - and my own commercial virus checker wasn't configured by default to do this!!
3. Update the 'virus signature files' regularly
Weekly updating of signature files should meet most people's needs.
Do not be put off by commercial sites such as Norton (Symantec) appearing to demand annual subscriptions for this. If you hunt around their websites you will find that updates of signature files are free for download - it is their fancy automated update facilities for which they charge (you may be prepared to pay for the convenience of this).
4. Check all suspect files
Any disc, including CD-Roms, should be checked, especially discs from friends!!
Downloaded files should also be checked, though commercial websites offering their own commercial software can probably be more trusted.
1. Don't panic
2. Follow the instructions in your virus-checking program - it will usually 'quarantine' the file to prevent it being opened, and may ask you to e-mail it to the program originators for examination.
3. Do not send e-mails or give discs created by your machine to anyone until you are sure the infection has been destroyed.
4. Read as much as you can about the virus causing the infection by going to your virus-checker's website; that will give you clear understanding of the threat it poses and enable you to help others who may be affected
We all receive e-mails with frightening-sounding 'virus alerts'. These are almost always hoaxes. If you have any doubts visit one of the websites listed here and search for the virus by name: you will then get realistic information about any risk. Do not pass on such alerts unless you have confirmation that the risk is genuine.
If you want to test that your anti-virus setup is working, go to:
http://www.eicar.com/anti_virus_test_file.htm
and follow the instructions there.
There is no room here to discuss other security issues which arise: but briefly here are some general points-
cookies are probably OK so don't worry about enabling them in your browser; many websites rely on them to function effectively
a 'firewall' program is probably not required unless your computer is locally networked - in which case you probably know all about firewalls (if you are interested in security issues for LANs check out http://cable-dsl.home.att.net/netbios.htm)
sending your credit-card number online: that's up to you! It is mostly very secure but the variations of security are endless; a good site will indicate what level of security it operates
encrypting e-mails: modern e-mail programs permit this facility; it is probably overkill except for very confidential information.
For general advice about security on Windows systems, check: http://www.Microsoft.com/security
Be aware that successive versions of Microsoft Operating Systems such as Windows 98 have had security 'holes' for which later patches have been issued. It is a good idea to check the Microsoft site every few months to see if any new security patches (usually small programs for downloading free and installing) have been issued.
Go to http://www.microsoft.com/downloads/search.asp and do a search on your Operating System name.
To get a free general report on your system's security level and advice on closing gaps go to:
http://www.Symantec.com/securitycheck
or
http://www.mcafee.com and go to 'Clinic'
and follow the instructions there.
Quintin A Blane
November 2000
Feedback and comments on this paper to qablane@surfaid.org