Q141720: Information Regarding Anti-Virus Scanners for Windows 95
Article: Q141720
Product(s): Microsoft Windows 95.x Retail Product
Version(s): WINDOWS:95
Operating System(s):
Keyword(s): win95
Last Modified: 17-DEC-2000
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Windows 95
-------------------------------------------------------------------------------
SUMMARY
=======
This article contains a copy of information from Microsoft about anti- virus
scanners in Windows 95.
MORE INFORMATION
================
Information Regarding Anti-Virus Scanners for Windows 95
--------------------------------------------------------
Recently there has been some information in the press and on the Internet about
the Windows 95 versions of some anti-virus scanners not detecting certain types
of files. This is not a problem with Windows 95 itself; rather, certain
anti-virus products may be incorrectly using the Win32 API (application
programming interface) to open and read files. A detailed technical explanation
of the issue is included below.
Microsoft is working closely with anti-virus vendors to help them resolve this
issue, and, to the best of our knowledge, no customers have been affected by
this issue. McAfee Associates is planning to release an updated version of their
anti-virus scanner that addresses this issue shortly. This page will be updated
as other anti-virus vendors update their anti-virus scanner applications.
Background
----------
The issue specifically relates to the way that the anti-virus scanners are
attempting to open filenames that contain special "OEM" characters on the US
code page (e.g., ASCII character 229). Code pages are internal tables that the
operating system uses to relate the keys on the keyboard to the characters
displayed on the screen. Different code pages provide support for the character
sets and keyboard layouts used in different countries. In order to open a
filename that contains these OEM characters, an application must use a specific
Win32 API call so that the default character set includes these OEM characters.
Anti-virus scanners detect infected files by first scanning the disk to obtain a
list of file names, and then analyzing (by opening and reading) the files found.
If the anti-virus scanner application does not use the 'SetFileApisToOem' Win32
API call before trying to analyze files, it may be unable to open file names
with these OEM characters. Using the above Win32 API call will allow the scanner
to successfully open and analyze all file names.
Additional query words: virus checker
======================================================================
Keywords : win95
Technology : kbWin95search kbZNotKeyword3
Version : WINDOWS:95
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.