Home » Archimedes archive » Micro User » MU 1992-03.adf » !VKiller/Docs/ExtendDoc

!VKiller/Docs/ExtendDoc

This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.

Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.

Tape/disk: Home » Archimedes archive » Micro User » MU 1992-03.adf
Filename: !VKiller/Docs/ExtendDoc
Read OK: ✔
File size: 1252 bytes
Load address: FFFFFF43
Exec address: 2B53B6BD
Duplicates

There are 7 duplicate copies of this file in the archive:

File contents
This is very detailed (although stopping short of a disassembly of course)
description of the Extend Virus. It is strongly recommended reading, if only to
give you a better understanding of how the virus operates.

Extend Virus technical information
----------------------------------

It's a module which can go under 8 different filenames (the name is picked at
random using the current time as a seed):

MonitorRM, CheckMod, ExtendRM, OSextend, ColourRM, Fastmod, CodeRM or MemRM.

Nowever, the module itself has the following title string:

Extend 1.56 (08 Jul 1989)

and is always known as "Extend" in the module list. For reference purposes,
I shall refer to it as the "Extend Virus".

The date seems to imply that it has been around for nearly 2 years, which is
a worrying thought indeed. It is 940 (&3AC) bytes long and initialises itself
as a nameless Wimp task which then looks for Wimp Message 5 (double-click).
It attempts to either create an !Boot in the application directory or append
to an already existing one with the following lines:

IconSprites <Obey$Dir>.!Sprites<&0D>
RMEnsure Extend 0 RMRun <Obey$Dir>.ModName<&0D>
||<&FF>

The "IconSprites" line is omitted if it is appended to an existing !Boot.
"ModName" is one of the 8 possible filenames. The Extend Virus uses the <&FF>
(i.e. decimal 255) byte at the end as a self-check to see if has infected the
!Boot file already. Of course, it copies itself to the new name inside
the application directory as you would expect. Note the incorrect use of
<&0D> (decimal 13) to terminate the lines, rather than the more correct
<&0A> (decimal 10).

A shift-double-click does NOT cause an infection, but it DOES claim yet
another 1K of never-to-be-released RMA.

I have gone through the entire code and the only destructive thing it does,
apart from wasting disk space with copies of itself, is to claim the 1K of
RMA for every double-clicked file or directory (eventually crashing the
system).

Extend Virus Execution Count
----------------------------

There was one bit of the Extend Virus module code that perplexed me - why
would someone increment a memory location within the module and never use it ?
At first I skipped this code, but, remembering some viruses on the Amiga, I
suddenly realised that the incremented value would be copied whenever the
module duplicated itself during a new infection. Now if the original author
was smart, he would have incremented the counter IF AND ONLY IF there was
a completely successful new infection (in fact, he would have incremented it
prior to the new infection and decremented it if the infection failed).
However, the Extend Virus module actually increments the counter whenever it is
first started (usually via the *RMEnsure appended to the !Boot)...thus the
counter does not correlate to the number of infections so far. Because of this,
I've decided to call it the "Execution Count" from now on.

Extend Virus deliberately faulty virus coding ?
-----------------------------------------------

When the Extend Virus initialises itself as a nameless task, it does not save
its task handle. Hence, when it comes to execute Wimp_CloseDown (only via a
*RMKill - it cannot be killed by the Task Manager) it does NOT supply a valid
task handle. Thus, opening up the Task Manager afterwards causes it to fatally
crash...which isn't nice.

Thanks to code supplied by Martin Avison, the task handle of the Extend Virus
task can now be determined at any time and it can be "patched" by VKiller so
that it shuts down with a proper task handle and the Task Manager can still be
safely used.

Extend Virus Innoculation
-------------------------

VKiller can innoculate a !Boot file. This involves fooling the Extend Virus
that it has already infected that !Boot file by attaching the following
to the end of the file:

IconSprites <Obey$Dir>.!Sprites<&0A>
| This file has been innoculated against the Extend Virus<&0A>
||<&FF>

The IconSprites line is only included if a new !Boot is created from scratch
AND if the application directory contains an !Sprites file with the Sprite
filetype. If the original !Boot was not properly terminated by a linefeed
(<&0A>), then a linefeed will be appended prior to the addition of any
innoculation lines. Note the critical difference between the Extend Virus
infection and the innoculation: the penultimate line is terminated by <&0A>
and not <&0D>. This is how VKiller can differentiate between innoculations
and infections.

Please note that creating new innoculated !Boot files from scratch will cause
the double-click action to open a directory window to take longer because the
applications inside that window have these new !Boot files.

00000000  54 68 69 73 20 69 73 20  76 65 72 79 20 64 65 74  |This is very det|
00000010  61 69 6c 65 64 20 28 61  6c 74 68 6f 75 67 68 20  |ailed (although |
00000020  73 74 6f 70 70 69 6e 67  20 73 68 6f 72 74 20 6f  |stopping short o|
00000030  66 20 61 20 64 69 73 61  73 73 65 6d 62 6c 79 20  |f a disassembly |
00000040  6f 66 20 63 6f 75 72 73  65 29 0a 64 65 73 63 72  |of course).descr|
00000050  69 70 74 69 6f 6e 20 6f  66 20 74 68 65 20 45 78  |iption of the Ex|
00000060  74 65 6e 64 20 56 69 72  75 73 2e 20 49 74 20 69  |tend Virus. It i|
00000070  73 20 73 74 72 6f 6e 67  6c 79 20 72 65 63 6f 6d  |s strongly recom|
00000080  6d 65 6e 64 65 64 20 72  65 61 64 69 6e 67 2c 20  |mended reading, |
00000090  69 66 20 6f 6e 6c 79 20  74 6f 0a 67 69 76 65 20  |if only to.give |
000000a0  79 6f 75 20 61 20 62 65  74 74 65 72 20 75 6e 64  |you a better und|
000000b0  65 72 73 74 61 6e 64 69  6e 67 20 6f 66 20 68 6f  |erstanding of ho|
000000c0  77 20 74 68 65 20 76 69  72 75 73 20 6f 70 65 72  |w the virus oper|
000000d0  61 74 65 73 2e 0a 0a 45  78 74 65 6e 64 20 56 69  |ates...Extend Vi|
000000e0  72 75 73 20 74 65 63 68  6e 69 63 61 6c 20 69 6e  |rus technical in|
000000f0  66 6f 72 6d 61 74 69 6f  6e 0a 2d 2d 2d 2d 2d 2d  |formation.------|
00000100  2d 2d 2d 2d 2d 2d 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |----------------|
00000110  2d 2d 2d 2d 2d 2d 2d 2d  2d 2d 2d 2d 0a 0a 49 74  |------------..It|
00000120  27 73 20 61 20 6d 6f 64  75 6c 65 20 77 68 69 63  |'s a module whic|
00000130  68 20 63 61 6e 20 67 6f  20 75 6e 64 65 72 20 38  |h can go under 8|
00000140  20 64 69 66 66 65 72 65  6e 74 20 66 69 6c 65 6e  | different filen|
00000150  61 6d 65 73 20 28 74 68  65 20 6e 61 6d 65 20 69  |ames (the name i|
00000160  73 20 70 69 63 6b 65 64  20 61 74 0a 72 61 6e 64  |s picked at.rand|
00000170  6f 6d 20 75 73 69 6e 67  20 74 68 65 20 63 75 72  |om using the cur|
00000180  72 65 6e 74 20 74 69 6d  65 20 61 73 20 61 20 73  |rent time as a s|
00000190  65 65 64 29 3a 0a 0a 4d  6f 6e 69 74 6f 72 52 4d  |eed):..MonitorRM|
000001a0  2c 20 43 68 65 63 6b 4d  6f 64 2c 20 45 78 74 65  |, CheckMod, Exte|
000001b0  6e 64 52 4d 2c 20 4f 53  65 78 74 65 6e 64 2c 20  |ndRM, OSextend, |
000001c0  43 6f 6c 6f 75 72 52 4d  2c 20 46 61 73 74 6d 6f  |ColourRM, Fastmo|
000001d0  64 2c 20 43 6f 64 65 52  4d 20 6f 72 20 4d 65 6d  |d, CodeRM or Mem|
000001e0  52 4d 2e 0a 0a 4e 6f 77  65 76 65 72 2c 20 74 68  |RM...Nowever, th|
000001f0  65 20 6d 6f 64 75 6c 65  20 69 74 73 65 6c 66 20  |e module itself |
00000200  68 61 73 20 74 68 65 20  66 6f 6c 6c 6f 77 69 6e  |has the followin|
00000210  67 20 74 69 74 6c 65 20  73 74 72 69 6e 67 3a 0a  |g title string:.|
00000220  0a 45 78 74 65 6e 64 20  31 2e 35 36 20 28 30 38  |.Extend 1.56 (08|
00000230  20 4a 75 6c 20 31 39 38  39 29 0a 0a 61 6e 64 20  | Jul 1989)..and |
00000240  69 73 20 61 6c 77 61 79  73 20 6b 6e 6f 77 6e 20  |is always known |
00000250  61 73 20 22 45 78 74 65  6e 64 22 20 69 6e 20 74  |as "Extend" in t|
00000260  68 65 20 6d 6f 64 75 6c  65 20 6c 69 73 74 2e 20  |he module list. |
00000270  46 6f 72 20 72 65 66 65  72 65 6e 63 65 20 70 75  |For reference pu|
00000280  72 70 6f 73 65 73 2c 0a  49 20 73 68 61 6c 6c 20  |rposes,.I shall |
00000290  72 65 66 65 72 20 74 6f  20 69 74 20 61 73 20 74  |refer to it as t|
000002a0  68 65 20 22 45 78 74 65  6e 64 20 56 69 72 75 73  |he "Extend Virus|
000002b0  22 2e 0a 0a 54 68 65 20  64 61 74 65 20 73 65 65  |"...The date see|
000002c0  6d 73 20 74 6f 20 69 6d  70 6c 79 20 74 68 61 74  |ms to imply that|
000002d0  20 69 74 20 68 61 73 20  62 65 65 6e 20 61 72 6f  | it has been aro|
000002e0  75 6e 64 20 66 6f 72 20  6e 65 61 72 6c 79 20 32  |und for nearly 2|
000002f0  20 79 65 61 72 73 2c 20  77 68 69 63 68 20 69 73  | years, which is|
00000300  0a 61 20 77 6f 72 72 79  69 6e 67 20 74 68 6f 75  |.a worrying thou|
00000310  67 68 74 20 69 6e 64 65  65 64 2e 20 49 74 20 69  |ght indeed. It i|
00000320  73 20 39 34 30 20 28 26  33 41 43 29 20 62 79 74  |s 940 (&3AC) byt|
00000330  65 73 20 6c 6f 6e 67 20  61 6e 64 20 69 6e 69 74  |es long and init|
00000340  69 61 6c 69 73 65 73 20  69 74 73 65 6c 66 0a 61  |ialises itself.a|
00000350  73 20 61 20 6e 61 6d 65  6c 65 73 73 20 57 69 6d  |s a nameless Wim|
00000360  70 20 74 61 73 6b 20 77  68 69 63 68 20 74 68 65  |p task which the|
00000370  6e 20 6c 6f 6f 6b 73 20  66 6f 72 20 57 69 6d 70  |n looks for Wimp|
00000380  20 4d 65 73 73 61 67 65  20 35 20 28 64 6f 75 62  | Message 5 (doub|
00000390  6c 65 2d 63 6c 69 63 6b  29 2e 0a 49 74 20 61 74  |le-click)..It at|
000003a0  74 65 6d 70 74 73 20 74  6f 20 65 69 74 68 65 72  |tempts to either|
000003b0  20 63 72 65 61 74 65 20  61 6e 20 21 42 6f 6f 74  | create an !Boot|
000003c0  20 69 6e 20 74 68 65 20  61 70 70 6c 69 63 61 74  | in the applicat|
000003d0  69 6f 6e 20 64 69 72 65  63 74 6f 72 79 20 6f 72  |ion directory or|
000003e0  20 61 70 70 65 6e 64 0a  74 6f 20 61 6e 20 61 6c  | append.to an al|
000003f0  72 65 61 64 79 20 65 78  69 73 74 69 6e 67 20 6f  |ready existing o|
00000400  6e 65 20 77 69 74 68 20  74 68 65 20 66 6f 6c 6c  |ne with the foll|
00000410  6f 77 69 6e 67 20 6c 69  6e 65 73 3a 0a 0a 49 63  |owing lines:..Ic|
00000420  6f 6e 53 70 72 69 74 65  73 20 3c 4f 62 65 79 24  |onSprites <Obey$|
00000430  44 69 72 3e 2e 21 53 70  72 69 74 65 73 3c 26 30  |Dir>.!Sprites<&0|
00000440  44 3e 0a 52 4d 45 6e 73  75 72 65 20 45 78 74 65  |D>.RMEnsure Exte|
00000450  6e 64 20 30 20 52 4d 52  75 6e 20 3c 4f 62 65 79  |nd 0 RMRun <Obey|
00000460  24 44 69 72 3e 2e 4d 6f  64 4e 61 6d 65 3c 26 30  |$Dir>.ModName<&0|
00000470  44 3e 0a 7c 7c 3c 26 46  46 3e 0a 0a 54 68 65 20  |D>.||<&FF>..The |
00000480  22 49 63 6f 6e 53 70 72  69 74 65 73 22 20 6c 69  |"IconSprites" li|
00000490  6e 65 20 69 73 20 6f 6d  69 74 74 65 64 20 69 66  |ne is omitted if|
000004a0  20 69 74 20 69 73 20 61  70 70 65 6e 64 65 64 20  | it is appended |
000004b0  74 6f 20 61 6e 20 65 78  69 73 74 69 6e 67 20 21  |to an existing !|
000004c0  42 6f 6f 74 2e 0a 22 4d  6f 64 4e 61 6d 65 22 20  |Boot.."ModName" |
000004d0  69 73 20 6f 6e 65 20 6f  66 20 74 68 65 20 38 20  |is one of the 8 |
000004e0  70 6f 73 73 69 62 6c 65  20 66 69 6c 65 6e 61 6d  |possible filenam|
000004f0  65 73 2e 20 54 68 65 20  45 78 74 65 6e 64 20 56  |es. The Extend V|
00000500  69 72 75 73 20 75 73 65  73 20 74 68 65 20 3c 26  |irus uses the <&|
00000510  46 46 3e 0a 28 69 2e 65  2e 20 64 65 63 69 6d 61  |FF>.(i.e. decima|
00000520  6c 20 32 35 35 29 20 62  79 74 65 20 61 74 20 74  |l 255) byte at t|
00000530  68 65 20 65 6e 64 20 61  73 20 61 20 73 65 6c 66  |he end as a self|
00000540  2d 63 68 65 63 6b 20 74  6f 20 73 65 65 20 69 66  |-check to see if|
00000550  20 68 61 73 20 69 6e 66  65 63 74 65 64 20 74 68  | has infected th|
00000560  65 0a 21 42 6f 6f 74 20  66 69 6c 65 20 61 6c 72  |e.!Boot file alr|
00000570  65 61 64 79 2e 20 4f 66  20 63 6f 75 72 73 65 2c  |eady. Of course,|
00000580  20 69 74 20 63 6f 70 69  65 73 20 69 74 73 65 6c  | it copies itsel|
00000590  66 20 74 6f 20 74 68 65  20 6e 65 77 20 6e 61 6d  |f to the new nam|
000005a0  65 20 69 6e 73 69 64 65  0a 74 68 65 20 61 70 70  |e inside.the app|
000005b0  6c 69 63 61 74 69 6f 6e  20 64 69 72 65 63 74 6f  |lication directo|
000005c0  72 79 20 61 73 20 79 6f  75 20 77 6f 75 6c 64 20  |ry as you would |
000005d0  65 78 70 65 63 74 2e 20  4e 6f 74 65 20 74 68 65  |expect. Note the|
000005e0  20 69 6e 63 6f 72 72 65  63 74 20 75 73 65 20 6f  | incorrect use o|
000005f0  66 0a 3c 26 30 44 3e 20  28 64 65 63 69 6d 61 6c  |f.<&0D> (decimal|
00000600  20 31 33 29 20 74 6f 20  74 65 72 6d 69 6e 61 74  | 13) to terminat|
00000610  65 20 74 68 65 20 6c 69  6e 65 73 2c 20 72 61 74  |e the lines, rat|
00000620  68 65 72 20 74 68 61 6e  20 74 68 65 20 6d 6f 72  |her than the mor|
00000630  65 20 63 6f 72 72 65 63  74 0a 3c 26 30 41 3e 20  |e correct.<&0A> |
00000640  28 64 65 63 69 6d 61 6c  20 31 30 29 2e 0a 0a 41  |(decimal 10)...A|
00000650  20 73 68 69 66 74 2d 64  6f 75 62 6c 65 2d 63 6c  | shift-double-cl|
00000660  69 63 6b 20 64 6f 65 73  20 4e 4f 54 20 63 61 75  |ick does NOT cau|
00000670  73 65 20 61 6e 20 69 6e  66 65 63 74 69 6f 6e 2c  |se an infection,|
00000680  20 62 75 74 20 69 74 20  44 4f 45 53 20 63 6c 61  | but it DOES cla|
00000690  69 6d 20 79 65 74 0a 61  6e 6f 74 68 65 72 20 31  |im yet.another 1|
000006a0  4b 20 6f 66 20 6e 65 76  65 72 2d 74 6f 2d 62 65  |K of never-to-be|
000006b0  2d 72 65 6c 65 61 73 65  64 20 52 4d 41 2e 0a 0a  |-released RMA...|
000006c0  49 20 68 61 76 65 20 67  6f 6e 65 20 74 68 72 6f  |I have gone thro|
000006d0  75 67 68 20 74 68 65 20  65 6e 74 69 72 65 20 63  |ugh the entire c|
000006e0  6f 64 65 20 61 6e 64 20  74 68 65 20 6f 6e 6c 79  |ode and the only|
000006f0  20 64 65 73 74 72 75 63  74 69 76 65 20 74 68 69  | destructive thi|
00000700  6e 67 20 69 74 20 64 6f  65 73 2c 0a 61 70 61 72  |ng it does,.apar|
00000710  74 20 66 72 6f 6d 20 77  61 73 74 69 6e 67 20 64  |t from wasting d|
00000720  69 73 6b 20 73 70 61 63  65 20 77 69 74 68 20 63  |isk space with c|
00000730  6f 70 69 65 73 20 6f 66  20 69 74 73 65 6c 66 2c  |opies of itself,|
00000740  20 69 73 20 74 6f 20 63  6c 61 69 6d 20 74 68 65  | is to claim the|
00000750  20 31 4b 20 6f 66 0a 52  4d 41 20 66 6f 72 20 65  | 1K of.RMA for e|
00000760  76 65 72 79 20 64 6f 75  62 6c 65 2d 63 6c 69 63  |very double-clic|
00000770  6b 65 64 20 66 69 6c 65  20 6f 72 20 64 69 72 65  |ked file or dire|
00000780  63 74 6f 72 79 20 28 65  76 65 6e 74 75 61 6c 6c  |ctory (eventuall|
00000790  79 20 63 72 61 73 68 69  6e 67 20 74 68 65 0a 73  |y crashing the.s|
000007a0  79 73 74 65 6d 29 2e 0a  0a 45 78 74 65 6e 64 20  |ystem)...Extend |
000007b0  56 69 72 75 73 20 45 78  65 63 75 74 69 6f 6e 20  |Virus Execution |
000007c0  43 6f 75 6e 74 0a 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |Count.----------|
000007d0  2d 2d 2d 2d 2d 2d 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |----------------|
000007e0  2d 2d 0a 0a 54 68 65 72  65 20 77 61 73 20 6f 6e  |--..There was on|
000007f0  65 20 62 69 74 20 6f 66  20 74 68 65 20 45 78 74  |e bit of the Ext|
00000800  65 6e 64 20 56 69 72 75  73 20 6d 6f 64 75 6c 65  |end Virus module|
00000810  20 63 6f 64 65 20 74 68  61 74 20 70 65 72 70 6c  | code that perpl|
00000820  65 78 65 64 20 6d 65 20  2d 20 77 68 79 0a 77 6f  |exed me - why.wo|
00000830  75 6c 64 20 73 6f 6d 65  6f 6e 65 20 69 6e 63 72  |uld someone incr|
00000840  65 6d 65 6e 74 20 61 20  6d 65 6d 6f 72 79 20 6c  |ement a memory l|
00000850  6f 63 61 74 69 6f 6e 20  77 69 74 68 69 6e 20 74  |ocation within t|
00000860  68 65 20 6d 6f 64 75 6c  65 20 61 6e 64 20 6e 65  |he module and ne|
00000870  76 65 72 20 75 73 65 20  69 74 20 3f 0a 41 74 20  |ver use it ?.At |
00000880  66 69 72 73 74 20 49 20  73 6b 69 70 70 65 64 20  |first I skipped |
00000890  74 68 69 73 20 63 6f 64  65 2c 20 62 75 74 2c 20  |this code, but, |
000008a0  72 65 6d 65 6d 62 65 72  69 6e 67 20 73 6f 6d 65  |remembering some|
000008b0  20 76 69 72 75 73 65 73  20 6f 6e 20 74 68 65 20  | viruses on the |
000008c0  41 6d 69 67 61 2c 20 49  0a 73 75 64 64 65 6e 6c  |Amiga, I.suddenl|
000008d0  79 20 72 65 61 6c 69 73  65 64 20 74 68 61 74 20  |y realised that |
000008e0  74 68 65 20 69 6e 63 72  65 6d 65 6e 74 65 64 20  |the incremented |
000008f0  76 61 6c 75 65 20 77 6f  75 6c 64 20 62 65 20 63  |value would be c|
00000900  6f 70 69 65 64 20 77 68  65 6e 65 76 65 72 20 74  |opied whenever t|
00000910  68 65 0a 6d 6f 64 75 6c  65 20 64 75 70 6c 69 63  |he.module duplic|
00000920  61 74 65 64 20 69 74 73  65 6c 66 20 64 75 72 69  |ated itself duri|
00000930  6e 67 20 61 20 6e 65 77  20 69 6e 66 65 63 74 69  |ng a new infecti|
00000940  6f 6e 2e 20 4e 6f 77 20  69 66 20 74 68 65 20 6f  |on. Now if the o|
00000950  72 69 67 69 6e 61 6c 20  61 75 74 68 6f 72 0a 77  |riginal author.w|
00000960  61 73 20 73 6d 61 72 74  2c 20 68 65 20 77 6f 75  |as smart, he wou|
00000970  6c 64 20 68 61 76 65 20  69 6e 63 72 65 6d 65 6e  |ld have incremen|
00000980  74 65 64 20 74 68 65 20  63 6f 75 6e 74 65 72 20  |ted the counter |
00000990  49 46 20 41 4e 44 20 4f  4e 4c 59 20 49 46 20 74  |IF AND ONLY IF t|
000009a0  68 65 72 65 20 77 61 73  0a 61 20 63 6f 6d 70 6c  |here was.a compl|
000009b0  65 74 65 6c 79 20 73 75  63 63 65 73 73 66 75 6c  |etely successful|
000009c0  20 6e 65 77 20 69 6e 66  65 63 74 69 6f 6e 20 28  | new infection (|
000009d0  69 6e 20 66 61 63 74 2c  20 68 65 20 77 6f 75 6c  |in fact, he woul|
000009e0  64 20 68 61 76 65 20 69  6e 63 72 65 6d 65 6e 74  |d have increment|
000009f0  65 64 20 69 74 0a 70 72  69 6f 72 20 74 6f 20 74  |ed it.prior to t|
00000a00  68 65 20 6e 65 77 20 69  6e 66 65 63 74 69 6f 6e  |he new infection|
00000a10  20 61 6e 64 20 64 65 63  72 65 6d 65 6e 74 65 64  | and decremented|
00000a20  20 69 74 20 69 66 20 74  68 65 20 69 6e 66 65 63  | it if the infec|
00000a30  74 69 6f 6e 20 66 61 69  6c 65 64 29 2e 0a 48 6f  |tion failed)..Ho|
00000a40  77 65 76 65 72 2c 20 74  68 65 20 45 78 74 65 6e  |wever, the Exten|
00000a50  64 20 56 69 72 75 73 20  6d 6f 64 75 6c 65 20 61  |d Virus module a|
00000a60  63 74 75 61 6c 6c 79 20  69 6e 63 72 65 6d 65 6e  |ctually incremen|
00000a70  74 73 20 74 68 65 20 63  6f 75 6e 74 65 72 20 77  |ts the counter w|
00000a80  68 65 6e 65 76 65 72 20  69 74 20 69 73 0a 66 69  |henever it is.fi|
00000a90  72 73 74 20 73 74 61 72  74 65 64 20 28 75 73 75  |rst started (usu|
00000aa0  61 6c 6c 79 20 76 69 61  20 74 68 65 20 2a 52 4d  |ally via the *RM|
00000ab0  45 6e 73 75 72 65 20 61  70 70 65 6e 64 65 64 20  |Ensure appended |
00000ac0  74 6f 20 74 68 65 20 21  42 6f 6f 74 29 2e 2e 2e  |to the !Boot)...|
00000ad0  74 68 75 73 20 74 68 65  0a 63 6f 75 6e 74 65 72  |thus the.counter|
00000ae0  20 64 6f 65 73 20 6e 6f  74 20 63 6f 72 72 65 6c  | does not correl|
00000af0  61 74 65 20 74 6f 20 74  68 65 20 6e 75 6d 62 65  |ate to the numbe|
00000b00  72 20 6f 66 20 69 6e 66  65 63 74 69 6f 6e 73 20  |r of infections |
00000b10  73 6f 20 66 61 72 2e 20  42 65 63 61 75 73 65 20  |so far. Because |
00000b20  6f 66 20 74 68 69 73 2c  0a 49 27 76 65 20 64 65  |of this,.I've de|
00000b30  63 69 64 65 64 20 74 6f  20 63 61 6c 6c 20 69 74  |cided to call it|
00000b40  20 74 68 65 20 22 45 78  65 63 75 74 69 6f 6e 20  | the "Execution |
00000b50  43 6f 75 6e 74 22 20 66  72 6f 6d 20 6e 6f 77 20  |Count" from now |
00000b60  6f 6e 2e 0a 0a 45 78 74  65 6e 64 20 56 69 72 75  |on...Extend Viru|
00000b70  73 20 64 65 6c 69 62 65  72 61 74 65 6c 79 20 66  |s deliberately f|
00000b80  61 75 6c 74 79 20 76 69  72 75 73 20 63 6f 64 69  |aulty virus codi|
00000b90  6e 67 20 3f 0a 2d 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |ng ?.-----------|
00000ba0  2d 2d 2d 2d 2d 2d 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |----------------|
*
00000bc0  2d 2d 2d 2d 0a 0a 57 68  65 6e 20 74 68 65 20 45  |----..When the E|
00000bd0  78 74 65 6e 64 20 56 69  72 75 73 20 69 6e 69 74  |xtend Virus init|
00000be0  69 61 6c 69 73 65 73 20  69 74 73 65 6c 66 20 61  |ialises itself a|
00000bf0  73 20 61 20 6e 61 6d 65  6c 65 73 73 20 74 61 73  |s a nameless tas|
00000c00  6b 2c 20 69 74 20 64 6f  65 73 20 6e 6f 74 20 73  |k, it does not s|
00000c10  61 76 65 0a 69 74 73 20  74 61 73 6b 20 68 61 6e  |ave.its task han|
00000c20  64 6c 65 2e 20 48 65 6e  63 65 2c 20 77 68 65 6e  |dle. Hence, when|
00000c30  20 69 74 20 63 6f 6d 65  73 20 74 6f 20 65 78 65  | it comes to exe|
00000c40  63 75 74 65 20 57 69 6d  70 5f 43 6c 6f 73 65 44  |cute Wimp_CloseD|
00000c50  6f 77 6e 20 28 6f 6e 6c  79 20 76 69 61 20 61 0a  |own (only via a.|
00000c60  2a 52 4d 4b 69 6c 6c 20  2d 20 69 74 20 63 61 6e  |*RMKill - it can|
00000c70  6e 6f 74 20 62 65 20 6b  69 6c 6c 65 64 20 62 79  |not be killed by|
00000c80  20 74 68 65 20 54 61 73  6b 20 4d 61 6e 61 67 65  | the Task Manage|
00000c90  72 29 20 69 74 20 64 6f  65 73 20 4e 4f 54 20 73  |r) it does NOT s|
00000ca0  75 70 70 6c 79 20 61 20  76 61 6c 69 64 0a 74 61  |upply a valid.ta|
00000cb0  73 6b 20 68 61 6e 64 6c  65 2e 20 54 68 75 73 2c  |sk handle. Thus,|
00000cc0  20 6f 70 65 6e 69 6e 67  20 75 70 20 74 68 65 20  | opening up the |
00000cd0  54 61 73 6b 20 4d 61 6e  61 67 65 72 20 61 66 74  |Task Manager aft|
00000ce0  65 72 77 61 72 64 73 20  63 61 75 73 65 73 20 69  |erwards causes i|
00000cf0  74 20 74 6f 20 66 61 74  61 6c 6c 79 0a 63 72 61  |t to fatally.cra|
00000d00  73 68 2e 2e 2e 77 68 69  63 68 20 69 73 6e 27 74  |sh...which isn't|
00000d10  20 6e 69 63 65 2e 0a 0a  54 68 61 6e 6b 73 20 74  | nice...Thanks t|
00000d20  6f 20 63 6f 64 65 20 73  75 70 70 6c 69 65 64 20  |o code supplied |
00000d30  62 79 20 4d 61 72 74 69  6e 20 41 76 69 73 6f 6e  |by Martin Avison|
00000d40  2c 20 74 68 65 20 74 61  73 6b 20 68 61 6e 64 6c  |, the task handl|
00000d50  65 20 6f 66 20 74 68 65  20 45 78 74 65 6e 64 20  |e of the Extend |
00000d60  56 69 72 75 73 0a 74 61  73 6b 20 63 61 6e 20 6e  |Virus.task can n|
00000d70  6f 77 20 62 65 20 64 65  74 65 72 6d 69 6e 65 64  |ow be determined|
00000d80  20 61 74 20 61 6e 79 20  74 69 6d 65 20 61 6e 64  | at any time and|
00000d90  20 69 74 20 63 61 6e 20  62 65 20 22 70 61 74 63  | it can be "patc|
00000da0  68 65 64 22 20 62 79 20  56 4b 69 6c 6c 65 72 20  |hed" by VKiller |
00000db0  73 6f 0a 74 68 61 74 20  69 74 20 73 68 75 74 73  |so.that it shuts|
00000dc0  20 64 6f 77 6e 20 77 69  74 68 20 61 20 70 72 6f  | down with a pro|
00000dd0  70 65 72 20 74 61 73 6b  20 68 61 6e 64 6c 65 20  |per task handle |
00000de0  61 6e 64 20 74 68 65 20  54 61 73 6b 20 4d 61 6e  |and the Task Man|
00000df0  61 67 65 72 20 63 61 6e  20 73 74 69 6c 6c 20 62  |ager can still b|
00000e00  65 0a 73 61 66 65 6c 79  20 75 73 65 64 2e 0a 0a  |e.safely used...|
00000e10  45 78 74 65 6e 64 20 56  69 72 75 73 20 49 6e 6e  |Extend Virus Inn|
00000e20  6f 63 75 6c 61 74 69 6f  6e 0a 2d 2d 2d 2d 2d 2d  |oculation.------|
00000e30  2d 2d 2d 2d 2d 2d 2d 2d  2d 2d 2d 2d 2d 2d 2d 2d  |----------------|
00000e40  2d 2d 2d 0a 0a 56 4b 69  6c 6c 65 72 20 63 61 6e  |---..VKiller can|
00000e50  20 69 6e 6e 6f 63 75 6c  61 74 65 20 61 20 21 42  | innoculate a !B|
00000e60  6f 6f 74 20 66 69 6c 65  2e 20 54 68 69 73 20 69  |oot file. This i|
00000e70  6e 76 6f 6c 76 65 73 20  66 6f 6f 6c 69 6e 67 20  |nvolves fooling |
00000e80  74 68 65 20 45 78 74 65  6e 64 20 56 69 72 75 73  |the Extend Virus|
00000e90  0a 74 68 61 74 20 69 74  20 68 61 73 20 61 6c 72  |.that it has alr|
00000ea0  65 61 64 79 20 69 6e 66  65 63 74 65 64 20 74 68  |eady infected th|
00000eb0  61 74 20 21 42 6f 6f 74  20 66 69 6c 65 20 62 79  |at !Boot file by|
00000ec0  20 61 74 74 61 63 68 69  6e 67 20 74 68 65 20 66  | attaching the f|
00000ed0  6f 6c 6c 6f 77 69 6e 67  0a 74 6f 20 74 68 65 20  |ollowing.to the |
00000ee0  65 6e 64 20 6f 66 20 74  68 65 20 66 69 6c 65 3a  |end of the file:|
00000ef0  0a 0a 49 63 6f 6e 53 70  72 69 74 65 73 20 3c 4f  |..IconSprites <O|
00000f00  62 65 79 24 44 69 72 3e  2e 21 53 70 72 69 74 65  |bey$Dir>.!Sprite|
00000f10  73 3c 26 30 41 3e 0a 7c  20 54 68 69 73 20 66 69  |s<&0A>.| This fi|
00000f20  6c 65 20 68 61 73 20 62  65 65 6e 20 69 6e 6e 6f  |le has been inno|
00000f30  63 75 6c 61 74 65 64 20  61 67 61 69 6e 73 74 20  |culated against |
00000f40  74 68 65 20 45 78 74 65  6e 64 20 56 69 72 75 73  |the Extend Virus|
00000f50  3c 26 30 41 3e 0a 7c 7c  3c 26 46 46 3e 0a 0a 54  |<&0A>.||<&FF>..T|
00000f60  68 65 20 49 63 6f 6e 53  70 72 69 74 65 73 20 6c  |he IconSprites l|
00000f70  69 6e 65 20 69 73 20 6f  6e 6c 79 20 69 6e 63 6c  |ine is only incl|
00000f80  75 64 65 64 20 69 66 20  61 20 6e 65 77 20 21 42  |uded if a new !B|
00000f90  6f 6f 74 20 69 73 20 63  72 65 61 74 65 64 20 66  |oot is created f|
00000fa0  72 6f 6d 20 73 63 72 61  74 63 68 0a 41 4e 44 20  |rom scratch.AND |
00000fb0  69 66 20 74 68 65 20 61  70 70 6c 69 63 61 74 69  |if the applicati|
00000fc0  6f 6e 20 64 69 72 65 63  74 6f 72 79 20 63 6f 6e  |on directory con|
00000fd0  74 61 69 6e 73 20 61 6e  20 21 53 70 72 69 74 65  |tains an !Sprite|
00000fe0  73 20 66 69 6c 65 20 77  69 74 68 20 74 68 65 20  |s file with the |
00000ff0  53 70 72 69 74 65 0a 66  69 6c 65 74 79 70 65 2e  |Sprite.filetype.|
00001000  20 49 66 20 74 68 65 20  6f 72 69 67 69 6e 61 6c  | If the original|
00001010  20 21 42 6f 6f 74 20 77  61 73 20 6e 6f 74 20 70  | !Boot was not p|
00001020  72 6f 70 65 72 6c 79 20  74 65 72 6d 69 6e 61 74  |roperly terminat|
00001030  65 64 20 62 79 20 61 20  6c 69 6e 65 66 65 65 64  |ed by a linefeed|
00001040  0a 28 3c 26 30 41 3e 29  2c 20 74 68 65 6e 20 61  |.(<&0A>), then a|
00001050  20 6c 69 6e 65 66 65 65  64 20 77 69 6c 6c 20 62  | linefeed will b|
00001060  65 20 61 70 70 65 6e 64  65 64 20 70 72 69 6f 72  |e appended prior|
00001070  20 74 6f 20 74 68 65 20  61 64 64 69 74 69 6f 6e  | to the addition|
00001080  20 6f 66 20 61 6e 79 0a  69 6e 6e 6f 63 75 6c 61  | of any.innocula|
00001090  74 69 6f 6e 20 6c 69 6e  65 73 2e 20 4e 6f 74 65  |tion lines. Note|
000010a0  20 74 68 65 20 63 72 69  74 69 63 61 6c 20 64 69  | the critical di|
000010b0  66 66 65 72 65 6e 63 65  20 62 65 74 77 65 65 6e  |fference between|
000010c0  20 74 68 65 20 45 78 74  65 6e 64 20 56 69 72 75  | the Extend Viru|
000010d0  73 0a 69 6e 66 65 63 74  69 6f 6e 20 61 6e 64 20  |s.infection and |
000010e0  74 68 65 20 69 6e 6e 6f  63 75 6c 61 74 69 6f 6e  |the innoculation|
000010f0  3a 20 74 68 65 20 70 65  6e 75 6c 74 69 6d 61 74  |: the penultimat|
00001100  65 20 6c 69 6e 65 20 69  73 20 74 65 72 6d 69 6e  |e line is termin|
00001110  61 74 65 64 20 62 79 20  3c 26 30 41 3e 0a 61 6e  |ated by <&0A>.an|
00001120  64 20 6e 6f 74 20 3c 26  30 44 3e 2e 20 54 68 69  |d not <&0D>. Thi|
00001130  73 20 69 73 20 68 6f 77  20 56 4b 69 6c 6c 65 72  |s is how VKiller|
00001140  20 63 61 6e 20 64 69 66  66 65 72 65 6e 74 69 61  | can differentia|
00001150  74 65 20 62 65 74 77 65  65 6e 20 69 6e 6e 6f 63  |te between innoc|
00001160  75 6c 61 74 69 6f 6e 73  0a 61 6e 64 20 69 6e 66  |ulations.and inf|
00001170  65 63 74 69 6f 6e 73 2e  0a 0a 50 6c 65 61 73 65  |ections...Please|
00001180  20 6e 6f 74 65 20 74 68  61 74 20 63 72 65 61 74  | note that creat|
00001190  69 6e 67 20 6e 65 77 20  69 6e 6e 6f 63 75 6c 61  |ing new innocula|
000011a0  74 65 64 20 21 42 6f 6f  74 20 66 69 6c 65 73 20  |ted !Boot files |
000011b0  66 72 6f 6d 20 73 63 72  61 74 63 68 20 77 69 6c  |from scratch wil|
000011c0  6c 20 63 61 75 73 65 0a  74 68 65 20 64 6f 75 62  |l cause.the doub|
000011d0  6c 65 2d 63 6c 69 63 6b  20 61 63 74 69 6f 6e 20  |le-click action |
000011e0  74 6f 20 6f 70 65 6e 20  61 20 64 69 72 65 63 74  |to open a direct|
000011f0  6f 72 79 20 77 69 6e 64  6f 77 20 74 6f 20 74 61  |ory window to ta|
00001200  6b 65 20 6c 6f 6e 67 65  72 20 62 65 63 61 75 73  |ke longer becaus|
00001210  65 20 74 68 65 0a 61 70  70 6c 69 63 61 74 69 6f  |e the.applicatio|
00001220  6e 73 20 69 6e 73 69 64  65 20 74 68 61 74 20 77  |ns inside that w|
00001230  69 6e 64 6f 77 20 68 61  76 65 20 74 68 65 73 65  |indow have these|
00001240  20 6e 65 77 20 21 42 6f  6f 74 20 66 69 6c 65 73  | new !Boot files|
00001250  2e 0a                                             |..|
00001252

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