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Chip 1996 December
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CHIP Aralık 1996.iso
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f-prot
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f-macrow.doc
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1995-11-09
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F-MACROW
F-MACROW is a 16-bit Windows application. It has been tested
successfully under Windows for Workgroups 3.11, Windows 95 and Windows
NT (3.51 and 4.0 beta 2), although it should work under plain Windows
3.1 as well. It does not work under DOS - but then, if you do not run
Windows the you do not have to worry about these viruses anyhow.
1. Installation.
To install F-MACROW, follow the simple procedure described below. (Future
versions will include an automatic installation program.)
1) Copy the file CTL3DV2.DLL to your WINDOWS\SYSTEM directory, if it is
not there already (the file is probably already in place). DO NOT keep a
copy of CTL3DV2.DLL in the same directory where F-MACROW.EXE resides or
you'll get an error message that the DLL is not properly installed.
2) The program needs the file OLE2.DLL in the WINDOWS\SYSTEM directory
too. However, if this file is not already on your system, WinWord 6.x or
above will not run, so macro viruses are not your concern.
3) Copy the files F-MACROW.EXE and MACRO.DEF in some directory (e.g.,
in the same directory where you have installed F-PROT). It doesn't
matter where they are placed but both of them must be in the same directory.
4) Create an item in some Program Manager group and make it point to the
file F-MACROW.EXE. (Alternatively, if you are using Windows 95, simply
drag the file from the Explorer and drop it on the desktop.)
2. Using F-MACROW.
Once you have installed the required files you can launch the program by
double-clicking the F-MACROW icon. Windows 95 users can also launch it
from the DOS prompt in a DOS box.
The program interface is very simple. The user clicks on the Scan button to
start the scanning. This brings up a dialog box, where the user can select
scanning options.
The following options are available:
Scan directory - Selects the directory to be scanned.
What to scan - Selects whether to scan files with standard extensions
for Word and Excel (*.DOC, *.DOT, *.XL?), or whether to
scan files with any extension.
Scan Subdirectories - Whether to scan the subdirectories of the specified
directory.
If a virus is found - Specifies what action should be taken if a virus is
found. The following options are available:
- Report only. Just reports the virus.
- Ask each time. The user will be asked each time
if the file should be disinfected.
- Disinfect automatically. The virus will be
automatically removed.
Report all scanned
documents - Normally the program will report only the files in
which a virus is found. If this option is checked,
all scanned files will be reported.
Report file - Check this option if you wish to save the report to a
file, and use the next two fields to specify the name
of the report file and whether the new report should
overwrite an already existing file or append to it.
When the desired options have been selected, press the OK button to start
the scan. The scanning can be stopped by pressing ESC or clicking the Stop
button.
To exit the program click on the Exit button.
3. Known problems.
- The Gangsterz virus is not disinfected perfectly: after disinfection,
the user has to open every disinfected document with Word, select
Tools/Customize/Keyboard/Reset All, and save the document back to
disk. This is because the virus makes somewhat unusual modifications
to the documents it infects. We know how to make the disinfection
perfect but just didn't have the time to implement it for this
release - the virus appeared just a couple of days before it.
- F-MACROW causes a GPF when scanning some documents. This is not our
problem. The documents are corrupted and Word (or any other
OLE2-enabled application) will crash when opening them too. The bug is
in Microsoft's STORAGE.DLL. A future version of F-MACROW will avoid
using this DLL.
- F-MACROW scans only OLE2 files. As a consequence, it will not detect
WordMacro viruses or Trojans in Word 2.0 documents. The format of
these documents is different than the format of the documents
produced by Word 6.0 and above, especially concerning the macro
structures. Microsoft still has not provided us with information
about these differences. If you don't like that F-MACROW cannot scan
for Word 2.0 viruses - complain to Microsoft.
- The user interface of F-MACROW is still rather rough and simplistic.
It cannot be run without user interaction, it cannot be told to scan
more than one subdirectory tree at a time, its window cannot be
resized, the on-line help has not been implemented yet and so on. All
this will be gradually fixed in the future versions.
- F-MACROW is a Windows application. It does not run under DOS. Please
use F-MACROW to scan and disinfect macro viruses - *NOT* F-PROT. If
F-PROT and F-MACROW disagree on whether a document is infected or
not - trust F-MACROW, not F-PROT. Please stop asking us to implement
F-MACROW's capabilities in F-PROT - this is not going to happen. The
OLE2 files in which Word 6.0 and above stores its documents have an
incredibly complex structure - in fact, they are whole file systems
in a file; with their FATs, root directory, subdirectories (called
"storages") and files (called "streams"). F-MACROW uses the standard
DLLs available in every Windows installation to parse the structure of
these files. Microsoft has provided us with the source of most of the
important functions in these DLLs but they are huge - about 150 Kb
when compiled. There is simply no space to put them in F-PROT. This
is why F-PROT does not understand the format of these files and
simply scans them for a scan string. This is slow, insecure, and
troublesome. It is slow because F-PROT cannot use its modern virus
locating algorithms which are applicable only for executable files.
It is insecure because a stream in the OLE2 file system can become
fragmented just like a file in the DOS file system - parts of it
which are logically consequent can be physically scattered all over
the OLE2 file. In practice this means that, if the fragmentation
occurs in the middle of the code which F-PROT uses as a scan string,
the scanner will not detect the virus. Admittedly, the probability
for this to happen is extremely low - but it is greater than zero
nevertheless and we cannot permit ourselves to provide an insecure
anti-virus program to our customers. Finally, F-PROT's method of
handling macro viruses is troublesome, because when some scanners
(e.g., Microsoft's SCANPROT) delete the macros of a macro virus, they
just mark them as deleted but leave the "dead body" of the virus
lying on the unused parts of the OLE2 file. Since F-PROT has no
knowledge of the OLE2 file structure, it cannot figure out that these
parts are unused and the virus in them is never executed. Therefore,
it can cause ghost positives - if it finds the scan strings of some
deleted macro virus there. All this will force us to remove macro
virus support from F-PROT.EXE in the near future. The users should
use F-MACROW instead. If they consider using two scanners instead of
one too much of an inconvenience, they should buy the Professional
version of F-PROT for Windows - it has no memory problems, so it can
have scanning for both kinds of viruses in the same program.
If any bugs are found, please report them to bontchev@complex.is, and if
you have any suggestions for improvements - feel free to e-mail to the
above address.
4. Version history.
Version 1.01:
- The report file changed to indicate how many infected files are still
left, how many files have been disinfected, and whether the user has
aborted the scanning process.
- A newer version of CTL3DV2.DLL included and the documentation
describing the installation process - updated.
- Some documents were reported as causing "Critical error". Fixed.
- Added detection, recognition, identification and removal for the
following new macro viruses:
Atom.B
Bandung
Colors.E
Gangsterz
Hassle
Nuclear.C
Wazzu.E
Wazzu.F
Version 1.00 (Beta):
First version released for public testing.
5. List of viruses detected by F-MACROW.
FormatC (Trojan)
Reflex.Dropper (Trojan)
Laroux (Excel)
Aliance
Atom.A
Atom.B
Bandung
Boom:De
Buero:De
Colors.A
Colors.B
Colors.C
Colors.D
Colors.E
Clock:De
Concept.A
Concept.B:Fr
Concept.C
Concept.D
Concept.E
Concept.F
Concept.G
Concept.H
Date
Dietzel:De
Divina
DMV
Doggie
Friendly:De
Gangsterz
Goldfish
Guess
Hassle
Hot
Imposter.A
Imposter.B
Irish
KillDLL
LBYNJ:De
MadDog
MDMA
NF
NOP.A:De
NOP.B:De
Npad
Nuclear.A
Nuclear.B
Nuclear.C
PCW:De
Pheeew:NL
Polite
Reflex
Satanic
Tedious
Wazzu.A
Wazzu.B
Wazzu.C
Wazzu.D
Wazzu.E
Wazzu.F
Xenixos:De