THD ProScan Version 6 is being released for the same reason
that Version 5 was released. "PKZIP" (ring any bells?). Anyway, with the 
release of PKZ204G the last (hopefully, sort of, yeah right) for a while, I 
have had to redo the code for self extracting ZIP files (yet again) so that 
it will recognize all of the SFX zip files.
     Therefore THD ProScan now recognizes all PKZIP files from 1.10 to 
2.04g.
     Since I was preparing another release anyway, I thought maybe I ought 
to add a few new toys.
     Support for the SQZ archive format has been added. It has a few 
differences from the other archive types. First the "stripping" of archive 
comments does not work (as this archive type will only take a file as 
input). But this is not a concern as it also does direct screen writes and 
therefore ansi bombs are not possible in it's comments. The adding of your 
own comment is operational as it is with the other archivers (although it 
may require a little more memory).
     Another quirk about SQZ is that it's use of memory is extravagant. When 
adding files to an archive, SQZ can require quite a lot of memory.(On my 
system, 525k). So, unless you have memory to spare SQZ may choke when 
attempting to add loaders to the archives. IF this operation fails due to 
lack of memory, THD ProScan will NOT fail the file, it will simply not add 
the loaders.
     SQZ can also erase the original archive under certain circumstances 
when attempting to add files or comments. To the best of my ability, I have 
disabled these functions when such a danger exists. If you encounter an 
instance where this happens please inform me so that I may take corrective 
action. The Author of SQZ.EXE has been informed of the problem.
     An RA user commented in regards to where and why THD moved and/or 
renamed files. He tells me that some BBS programs handle failures in a more 
intelligent manner than Telegard and asked if this option could be disabled.
Therefore beginning with Version 6, a parameter of "/NOMOVE" when running 
THDINSTL.EXE will insert code into THDPRO.EXE telling it NOT to move or 
rename files. This code is reset every time the installation is run and must 
be repeated each time the software is re-installed or it will default back 
to moving the files. I recommend against using this option unless your BBS 
program saves failed files (remember files can fail for more than one 
reason).
     A potential problem was brought to my attention. Someone queried as 
to what might happen if THDPRO.EXE were run on two nodes of a BBS at the 
same time. Basically, prior to version 6, both would write files to the same
directory and make log entries at the same time. The premature deletion of 
the files to be tested would undoubtedly cause one of the tests to fail.
Therefore THD ProScan will no longer use a directory called THDTEMP.$$$. 
Instead it will use THDTEMP.$$#, where "#" is the comport number running 
the test. This will keep the files separated for testing purposes. The 
logs will be written to temporary files which will be appended to THDPRO.LOG
at the completion of their running.
     That same user noted a problem whereby he uses a node 3 on his bbs for 
local logons and was unable to have the BBS pass a "0" for node 3 to suppress 
the remote output. An option has been added to the installation which allows
THDPRO.EXE to treat a specific comport as "0". Therefore, if you have node 3 
as a local only node, during the install you can enter a "Local Comport" of 
"3" (when asked) and all requests to THDPRO.EXE for processing to comport 3
would then be diverted to comport "0". (Note that the "3" in this discussion
is only an example and that any number from 0 to 8 is valid).

     The most noteable addition to this version, is the inclusion of 
"heuristic" testing. Heuristic testing is the testing of files for 
"suspicious" code. While some of these types of code are present in many 
programs, it aids greatly in the identification of unknown viruses.
     This version will support one of two testers for this purpose. Either 
TBSCAN.EXE or F-PROT.EXE. Since suspicious code is present in many 
legitimate files, THD ProScan will not fail any file due to this form of 
testing but will keep a log and inform you if suspicious code is indeed 
found.
     A log called "HEURIST.LOG" will contain the log output from these 
testers and should be deleted occassionally to avoid having them become 
unreasonably large. Entries will only be made when suspicious code is found. 
This log will be in the same directory as your THDPRO.LOG. The main virus 
scanning will still be done by McAfee's SCAN.EXE and these two testers will 
be used ONLY for heuristic testing.
     Of the two testers, I personally would recommend TBSCAN.EXE for 2 
reasons. First, it is MUCH faster than F-PROT.EXE and it gives considerably 
more information (although this also results in more "suspicious" files). 
Also F-PROT.EXE seems to require a lot of memory ( I get a memory shortage 
running from a dos prompt with a few TSR's loaded). So unless you have a LOT 
of spare memory in your shell from your BBS program, F-PROT.EXE may not even 
run for you.
     Memory reductions during those tasks which require a lot of memory has 
been achieved through the use of TurboPower Software's EXECPATH. This 
function is active during the running of all "SQZ, SCAN, and F-PROT" 
activity, which results in a memory savings of approximately 48k during 
these tests/functions.

     The introduction of encryption into the THDPRO.EXE file makes the file 
much smaller and means that the executable file cannot be compressed. Any 
successful attempt at reducing the file will result in the program not 
working. Also some virus scanners may attempt to add a CRC to the end of the
file, If yours does this, be sure to stop it from affecting THDPRO.EXE as 
such a change to the file will render it inoperable.
     Therefore it is no longer recommended that the executable be shrunk by 
any such compressor.
     That's all Folks...