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Re: [suse-security] Postfix and w32.swen.A



On Tue, 23 Sep 2003, Vaclav made the net somewhat safer by saying:

> Hello,
> 
> recently I have introduced to postfix the mime_header_check with the 
> rule to bounce messages including attachments with executable files 
> based on a suggestion in this list. I have tested that and it seemed 
> to work fine. Nevertheless since Sunday I am receiving (and other 
> users of the server, too) many mails containing the w32.swen.A. It's 
> strange, as this mail contains a file xxxx.exe attached. Is there a 
> way to modify the postfix conffiguration to stop these (and may be 
> similar mails in the future) mails? Seems that this type of 
> attachment bypasses somehow this filtre. I have checked the message, 
> and did not find a difference with otrher types of attachments.

Check Ralf Hildebrandts site
<http://www.stahl.bau.tu-bs.de/~hildeb/postfix/postfix_sobigf.shtml>

I'm using simpel headerchecks on the Subject and From myself, plus a
message_size_limit of 64kB, which seems effective enough.

/^Subject:.*Last Net Pack/
    DISCARD Possible virus, don't need it anyway
/From:.*(microsoft|ms)\s+(internet|corporation|program|technical|customer|email|network)/
    DISCARD Possible virus, don't need it anyway
/From:.*(customer|security)\s+(assistance|service|bulletin)/
    DISCARD Possible virus, don't need it anyway
/From:.*network\s+message/
    DISCARD Possible virus, don't need it anyway

All pcre.

Theo
-- 
Theo v. Werkhoven    Registered Linux user# 99872 http://counter.li.org
ICBM 52 13 27N , 4 29 45E.
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See headers for PGP/GPG info.

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