gnupg encrypted mail and malware/spam

[Per Tunedal]

At 13:28 2003-05-11 +0200, you wrote:

 >'I do not fear 'ordinary' viruses or other malware. What i really fear
 >is a sophisticated attacker that send on a very slow rate backdoors to
 >single users in my network. I can not guarantee the really no user will
 >start the program. If it is started, it's easy to create a backchannel
 >over allowed traffic like http.'
 >
 >Does nobody fear this, too? I'm very surprised that this threat was
 >never discussed in the context of public key infrastructures.
 >Hoping for more comments and suggestions,
 >
 >Yours,
 >
 >Thomas

Hi again Thomas,
did you read my mail about stopping unknown software from running on the 
client? I believe it is a step forward that such software is available from 
at least 2 different developers. It's quite popular to use Abtrusion 
Protector to "lock" computers at Swedish schools. Wouldn't the same kind of 
solution be applicable at your company?
Per Tunedal