Thanks for looking at this Igor. Sorry I didn't supply more help last night at 0100 hours.
Example download 'detection updates' (filename: spybotsd_includes.exe)
from URL
http://www.safer-networking.org/en/download/index.htmlI get a different MD5 hash for each copy downloaded when Web Shield is ON. I have seen correct MD5 hash when Web Shield is ON but it rarely happens.
When Web Shield is OFF, MD5 hash is the same for each copy of the file.
The problem seems to be general to any downloaded .exe file. I have not noticed if any other file type is also affected.
I am running a fully patched Windows XP Pro SP3. I use Agnitum Outpost Firewall Pro 7.0.4 (3412.520.1245). There is no other real time security software. Avast File System Shield is set to exclude the Agnitum folder in Program Files. All other installed security software is for on-demand scanning only.
Oops! I forgot to say that I also use Trusteer Rapport (build 1005.71) and that the problem persists even when Agnitum Outpost Firewall Pro Web Control feature is disabled.
I do my best to supply further information.