BOOT CAMP 004
BUG -- COMPUTER VIRUSES
Friday the 13th occurs three times in 1998, it’s going to be
a worrying year for superstitious PC owners. It’s a favourite date for
triggering computer viruses but relax,
the chances of your PC catching a nasty infection are actually quite small,
provided you take a few simple precautions.
Nevertheless, the risk exists and with the growth of the PC
population, the internet and the ingenuity of virus creators, it is increasing
all the time. But what exactly is a computer virus, and what are the dangers to
Broadly speaking a virus is any program that gets into your
PC, without your permission, and interferes with its normal operation. At the
last count there were more than 15,000 of them. As it happens most are
relatively benign and do little actual harm, apart from messing around with the
display or putting up irritating messages on the monitor screen. Others though
can do real damage, to the data on your PC or the network, by scrambling or
concealing files, causing unpredictable behaviour. In extreme cases a virus can
trash the hard disc drive in your computer, where all of your programs and files
Viruses come in all shapes and sizes but they’ve all got
individual characteristics or ‘signatures, that can be identified by up-to-date
anti-virus scanning software. Some of the hardest to detect lurk in the Master
Boot Sector, that’s an area of your hard disc containing important software,
that controls how your PC operates. From there viruses can spread to floppy
discs and infect other machines.
Almost as virulent are memory resident or TSR file viruses,
which can also take over a PCs operating system and make it do unpleasant things
to files and data. They live quietly in the computer’s memory and spread by
infecting files containing programs and drivers. They’re the ones that end in
the letters .EXE, .COM or .SYS.
Stealth and polymorphic viruses are cunning little devils.
They’re a bit like their biological counterparts. They can change their
appearance and incorporate themselves into legitimate pieces of software, making
detection and eradication that much more difficult. Some hide by making sure
that the size of the host program doesn’t change, after it has been infected.
Others alter their signature code after each infection, to avoid being
identified by scanning software
Macro viruses are comparatively new and a threat tp PCs
running word processing and spread sheet programs. They’re written in a
programming language that makes the program perform a repetitive task or
‘macro’. The trouble is, macros can be hidden inside text and data files and
easily transferred from PC to PC via infected discs and Email. Once the file is
opened the virus goes about its business, changing and corrupting other files.
Incidentally, your PC cannot become infected by plain text
Emails. Viruses are be hidden inside attachments and programs, and they only
become active when they’re opened or executed. It’s fair to say that the
Internet is generally safe, though it’s sensible to avoid downloading material
from obscure or suspicious-looking sites.
If your PCs is mostly used for game playing or
word-processing then you haven’t much to worry about. The odds start to rise
when your machine is connected to the internet or a network, you swap discs with
other PC owners or you buy bootleg and pirate software. The odd virus has also
popped up on free magazine cover mounted CD ROMs. If your PC falls into any of
those categories, you have already experienced an infection or your machine is
behaving erratically, then it’s time to get hold of some anti-virus software.
Most anti-virus programs carry out a preliminary scan as
they’re loading, so you start with a clean slate. After that they check
vulnerable areas of your disc drive and memory, every time the PC is switched
on. All new software coming onto the machine is checked, whether it’s on disc,
CD-ROM or downloaded from the internet.
Anti-virus software is only as good as its signature library.
Most programs can be updated, with signatures of the newest viruses, either
automatically from the manufacturer’s internet web site, or on floppy disc.
If an infection is detected scanning software immediately
puts up a warning message on the screen, and stops any further potentially
damaging disc writing activities. The affected files are then isolated or
‘quarantined’, so they can be safely disinfected, deleted or renamed, if the
software regards them as harmless.
Don’t get paranoid but do take precautions. There’s only
three weeks to go before February Friday the 13th!
ANTI VIRUS SOFTWARE
Cheyenne Anti Virus £48
Roderick Manhatten Group Ltd., 0181-875 4441
Dr Solomons Anti Virus Toolkit, Win 95, £80
Dr Solomon UK, telephone (01296) 318700
McAfee VirusScan V3,
McAfee, telephone (01344) 304730
Norton AntiVirus Deluxe 4.0, £50
Symantec UK, telephone 0171-616 5600
PC-cillin 95, £34
Roderick Manhatten Group Ltd., 0181-875 4441
Sophos Anti-Virus 3.0, £120
Sophos plc, telephone (01235) 559933
Extensions -- files ending in .EXE or .COM usually contain
executable programs; .SYS files are mostly used for driver software, used by the
PC to communicate with hardware devices
SoHo -- small office/home office
TSR -- terminate and stay resident, programs that load
automatically into the computer’s memory and operate in the background until
From the Start menu in Windows 95 click on Settings, Control
Panel, and then on the Mouse icon. There you will find a range of settings, that
control the way your mouse behaves. There’s also the opportunity to change the
button configuration, useful if you are left-handed. The two most important
parameters for PC newcomers are Motion and Click Speed; set both to slow and
you’ll find the mouse much easier to control. Increase the speed once you get
used to how the mouse reacts. Whilst you’re there click on the Pointers tab and
the Scheme menu, then select the Animated Hourglasses option. This will make
waiting for things to happen just a little more interesting...