
                      !KillVirus by Stuart Tyrrell
                      ============================

                         Version 1.00 (10/05/91)
                         =======================

This is KillVirus, written by Stuart Tyrrell. The program and its associated
files are Public Domain, and may be distributed freely, providing no charge
is made for the programs, and that the files remain intact and unaltered.
Any alterations / suggestions etc should be sent to me, and I will be able
to issue a new version number for new versions.

The program will remove the EXTRA virus from an infected disk, and will
remove and innoculate disks against the EXTEND virus. It will also remove
EXTEND from the RMA, although it does not perform the "fix" that you will
find on RKL's VKiller program, and so I advise you not to have any other
applications running when you use KillVirus, and that you press Ctrl-Reset
if a virus is found.


USING THE PROGRAM
=================

Double click on the !KillVirus icon from the filer window. The application
will load and appear on the icon bar.

To use the program, click Select on the icon on the icon bar. A window will
appear. Within the window there are a few icons :

Status : This shows you what is happening - how the scan is progressing, etc

Directory to scan from : Writing in this icon allows you to select which
drive and directory are scanned. For example, to scan an ADFS disk called
'FredDisk, you would enter

                           ADFS::FredDisk.$

The line

                           ADFS::0.$

means the ADFS disk in drive 0.

Remove Viruses : Selecting this icon will make the program remove a virus
from disk if one is found.

Make !BOOTs : Selecting this icon will add an inocculated !BOOT to each
application, ensuring that they cannot be infected by EXTEND in the future.

Innoc. !BOOTs : Selecting this icon will make the program innoculate
existing !Boot files against the EXTEND virus.

Go ! : Well................


THE "EXTRA" VIRUS
=================

A copy of this virus was sent to me (clearly marked!) last week. The virus
possibly originated from someone under the title of "Packet Man". If anyone
knows of this person, there are a few people who wish to talk to him/her
(such as Scotland Yard).

The virus is written in BASIC, and is hidden in a file called "ICON", which
is filetyped as a sprite. The virus adds some lines to the !BOOT file of an
application, which ensures that it is loaded into memory when the disk is
catalogued. Once in memory, the virus will replicate itself into files on
any disk that is inserted and catalogued.

Sometimes, (about 1 times in 8), when the program is first installed, it
produces a silly message. While these are quite funny (such as "Data Bank
Error in You Favour", and "No conductor found on data bus"), they are an
indication that the virus is present.

Every time that a directory is found which has the virus present, it loads
itself into memory, as a 16K "nameless task". Again, lists of 16K bars with
no names on the Task Display are an indication that the virus is present.

Full details of the virus may be obtained from me. I must be convinced,
however, that they will not be misused.


KILL VIRUS' ACTIONS
===================

Kill Virus searches through the !Boot files for the lines which load up the
EXTRA virus, and overwrite them with commented lines if they are found. The
program also removes the virus program itself - "ICON".

Kill virus also provides protection against EXTEND. The program will
innoculate against the virus in the same way as RKL's VKILLER does. The
program will also remove the virus from disk, and from memory. Unfortunatly,
KillVirus will not "fix" the EXTEND virus in the same way as RKL's VKiller
does, but then, VKiller does not provide protection against EXTRA (although
I've sent the details on to RKL)


THANKS
======

Thanks go to the person who sent me the virus and details of its actions (it
took over 4 Megs of his hard disk before he found it!).    :-(

Thanks goes to Richard K LLoyd for writing VKILLER.
                                                

PROGRAM HISTORY
===============

V0.01  Initial "emergency" program (monotasking)

-Realised a number of bugs :
                          * Would not innoculate !BOOT files which were not
                            write enabled - program crashed

                          * The program did not look nice - it looked as
                            though it was "rushed" (it was - it took an
                            afternoon's programming!)

So, set about to write :

V1.00  Much nicer, as you can see!



ADVERT
======

Have you seen STUDEMOS1-6? Have you played PLANETLAND? They are available
from most PD's!

CONTACT
=======

I may be contacted at the following address :

Stuart Tyrrell
c/o 2, Woodside Ave
Moss Bank
St. Helens
Merseyside
WA11 7BS

The original program was written in one afternoon (01/05/91), one pack of
McVities Rich Tea, and seven glasses of orange.

This "new improved version" was written from 9.30pm to 3.20am, 09/05/91 -
10/05/91, and I've run out of buscuits!
                                 
Stuart Tyrrell 10/05/91         {:-)