This is what I'm using for blocking executable files and it seems to work
well...

/etc/postfix/main.cf:
  mime_header_checks =
   pcre:/etc/postfix/mime_header_checks.regexp

/etc/postfix/mime_header_checks.regexp:

/name=[^>]*\.(ade|adp|bas|bat|chm|cmd|com|cpl|crt|exe|hlp|hta|inf|ins|isp|js
|jse|lnk|mdb|mde|msc|msi|msp|mst|pcd|pif|reg|scr|sct|shs|url|vb|vbe|vbs|wsc|
wsf|wsh)[\'\"]/ REJECT ACL mime_banned_file


Bill

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Gerry Massat
Sent: Wednesday, February 25, 2004 10:12 PM
To: [EMAIL PROTECTED]
Subject: [IMGate] Re: Netsky.C


Cybertime Hostmaster wrote:

>The newest rage in viri, Netsky.C, hit one of the machines here.  Just a
>heads up on this little bugger:
>
>http://www.sarc.com/avcenter/venc/data/[EMAIL PROTECTED]
>
>It went past the anti-virus until there was an update made specifically
>for it.
>
>It put 8010 copies of itself on the infected machine.
>
>And it mass mails like nuts.
>
>
(snip)

>Anyone found a good body check for this one yet?
>
>--Eric
>
According to sarc- 'Name of attachment
<http://securityresponse.symantec.com/avcenter/refa.html#name>: varies
with .com, .exe, .pif, or .scr file extension'
Are you rejecting executable attachments?  I've been using this in
header_checks.regexp-

/^\s*Content-(Disposition|Type).*name\s*=\s*"?(.*\.(ad[ep]|ba[st]|chm|cmd|co
m|cpl|crt|dll|eml|exe|hlp|hta|in[fs]|isp|jse?|lnk|md[betw]|ms[cipt]|nws|ocx|
ops|pcd|p[ir]f|reg|sc[frt]|sh[bsm]|swf|vb[esx]?|vxd|ws[cfh]))(\?=)?"?\s*(;|$
)/x
REJECT Attachment name "$2" not accepted with ".$3" extension

and Len's checks that came in body_checks.regexp- for example:

/^(content.*[[:space:]]+|[[:space:]]*)(filename|name)=".*\.(htm|html|exe|EXE
|ex_|EX_|eml|dll|scr|pif|com|bat|shs|shb|vxd|rm|chm|vbs|ini|cmd|do|hta|reg|l
nk|js|jse|net)"/
HOLD REJECT Body filter 3

Notice the hold- there are other tests in body_checks.regexp, and so far
nothing has been held.  The header checks seem to catch everything.
Gerry.



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