Zyra's
website
//// site index //// Computers //// Virus
Information and Misconceptions //// Examples
of Viruses
//// Advice
Anti-Virus
Measures
*
How to Avoid Getting a Virus in Your Computer *
As
well as looking at the page of Anti-Virus
software, there is an alternative way of
looking at avoiding getting viruses. This page you are reading
now is a Free AntiVirus system, which you don't download into
your computer. This anti-virus system is for loading into your
own memory, as the methodology you understand will help to save
your computer.
- If
you are using Windows, set the "hide file extension"
option to Not Hide
file extensions. This simple method would have defeated
the Love Bug
virus, as it had a file with .txt.exe on the end.
Similarly, files ending with .doc.com are to be
considered suspicious and anything with .something.something-else
needs a second look! (If anyone sends you one of these,
don't accuse them - it's almost certainly not their fault.
Their computer has been infected. Send them a polite
message telling them, and if you don't get a reply, use
the fax/phone and make sure they know!)
- When
starting up a computer, make sure that there is no
unintentional floppy disc in the drive. Also, don't have
the option set to auto-run CDs.
- Never
run an attachment on an e-mail
unless you are sure it is not executable, (unless of
course you know it is from a friend and you are sure that
they intend it to be executable). In particular, never
run tempting but anonymous items in an attempt to satisfy
curiosity. To see examples of this, see the Rogues
Gallery of suspicious e-mails. Attachments ending
in .exe , .bat , .scr , .com , .pif , and a few others
are executable and therefore a potential risk! Also, .zip
is a potential risk because of auto-executables and other
bad assumptions. For example, see uniform traffic ticket and other such
roguery.
- When
using the Internet on a dial-up phone connection, have a Charge
Advice option set on your phone.
That way, if anything attacks your dial-up system so it
starts charging you a fortune for premium-rate services,
you will know straight away.
- Include
yourself in your address book. That way if you catch a
virus (which will try to send to people in your address
book) you'll probably get a message from yourself which
you won't expect, giving rise to suspicion. Also, having
friends in your address book aware of virus risks, may
get you an early warning of any infection. Another method
which is worth knowing about is... !000
- Don't
allow ActiveX and cookies to run automatically with no
safeguards. Much better to set them to "prompt".
(See how to do this).
It is especially important to stop ActiveX arriving in e-mails!
If you receive ActiveX in e-mails or on sites that you
are suspicious of, beware! (Also see ActiveX
and other bad practices).
This has become even more important now. ActiveX in an e-mail
is almost always a virus. Don't allow it! Be aware of the
problem of the Preview Pane. If you want to be
able to receive silly spam messages and visit suspicious
tempting sites such as the TERRAKT
IN AUSTRALIA thing, then don't allow
Active Scripting either!
- Keep
several backups of everything, and if a virus is
discovered, be very careful what you do with the backup
material. You can even be paranoid.
- Remember
that data lost as a result of deletion, some types of
formatting, and even emptying of recycle bins Is
Not Final. Often it is possible to
recover lost data by using some very clever techniques.
To give yourself the best possible chance of these
techniques working, if things go completely wrong and you
think it's all lost, don't do anything - just turn it all
off until it can be expertly and calmly examined. Data Recovery experts
include such companies as ESS
Data and Kroll
Ontrack, and now Palmer and
Xytron too.
Miracle workers, but possibly expensive? Have a look and
find out. But then again, your data is worth it, isn't
that right?
- Consider
some antivirus software but
remember that although it will help, it won't make you
immune to viruses. Even if your antivirus software says
"No virus found", if the attachment is a .exe ,
it's almost certainly a virus!
- Windows95/98
when it was still supported was better than Windows2000/NT/XPire/Vista at
virus-avoidance because it couldn't catch things like the
Red Worm. LINUX is
better still, partly because it's Unix and a lot of this
"virus" stuff has been dealt with a long time
before, and partly because of the better way bugs are
dealt with (ie fixed), and also because Linux machines
are not all the same as each other, which makes them more
difficult to attack.
- Be
aware that there are such things as the "sulfnbk
virus" which is Not a
computer virus but is a hoax which spreads like a virus
because of people being urged to forward the virus
warning message. (The warning about "jdbgmgr.exe"
is a similar hoax, with such things as deleting a teddy
bear etc, and so is the pavlo
88 message). Any message with
"tell everyone in your address book" should be
considered carefully (see chain
letters) and if in doubt, key
phrases looked up on a search
engine to see what reports there
are about the situation. Reports should be checked too!
Those at Norton, McAfee, Kaspersky,
etc can be assumed quite reliable.
- Remember
that if someone sends unsolicited a free screensaver or a
free virus executable tool, they are at very best
recklessly irresponsible, and at worst virus-sending
culprits! e-mail Postcards from people you don't know,
are often spam and
are sometimes viruses.
- Messages
apparently from banks aren't real. See bank
hoax
- It's
worth knowing about some of the well-known titles and
types which are known viruses, and to check for them. For
example, shaking friends screensaver, anything
with "goldfish" in the subject line,
and any very brief messages that just say "check the
attach". Also see Rogues
Gallery of Suspicious e-mails and the examples
of viruses
- Also
be aware of a particularly nasty trick where a message
arrives pretending to be an official virus warning from
Microsoft and imploring you to run a .exe file in an
attachment. Don't! See Microsoft
Message hoax!
- Similarly,
warnings about viruses such as Klez-E claiming to contain
a cure for it, have to be considered as they can often be
the virus themselves. More about the ridiculous Klez
E
hoax here.
- Viruses are
also sometimes disguised as "Mail returned"
messages which pretend to be regarding items you have
sent, or are supposed to be horrified about as you have
not sent them. See Mail-Returned virus
messages. This can easily be defeated
by knowing what you have sent and/or having separate send
and receive addresses. Again, don't run the attachments.
- How
to Test if Your Computer has Caught a Virus - without having to
run any software!
- A Virus or no
Virus? That isn't the end of the story, as a computer can
be infested with something that's not officially "a
virus" and yet is still a nuisance. See Spyware and how to
eliminate it. Also, don't let someone control your
browser default homepage! See how
to define your own homepage
- QR Codes (those
square matrix blocks with pixels for your mobile device
to read). These generally do not contain malicious stuff
in themselves. However, they can contain links to
websites some of which are bad. To avoid the problem of
"Malicious QR Codes", you need to set your
mobile device to "preview URL". Don't allow
incoming stuff to run automatically, or you will sooner
or later come a'cropper. Also, don't believe everything
you read. It's the deceptive descriptions which are
malicious rather than the codes themselves.
- If someone
phones you are says your computer has a virus, say "how
do you know?" and read this page on the phone virus hoax. You don't have to
believe the caller, and you don't have to do what they
say. They are scamsters, generally.
This
page is to be considered like the safety advert on television
where you see how to put a wet tea-towel over a flaming chip pan.
The advice is useful, and you don't have to learn it all, but
just think about it, as even some of these simple things could
save you a lot of trouble. Only time and experience will tell
whether it's too late to save your chips.
This
advice-based antivirus system is being continuously adapted to
defend against new problems. If you've ever been attacked by a
virus and can help others learn how they can be defended against
it, please e-mail here
Readers of printed
copies of this page please note that it can be found online at www.zyra.org.uk/avirus.htm
If your computer
caught a virus and sent it to me before 2002/08/05 I would have
most likely sent you my Anti-Virus Letter. Not anymore though! Not
since... read it and find out