#alert tcp $EXTERNAL_NET any -> $HOME_NET 25 (msg:"BLEEDING-EDGE VIRUS Bagle.CJ SMTP Inbound"; flow:to_server,established; content:"UEsDBBQAAAA"; content:"EEkIAAAG"; distance:12; within:20; reference:url,isc.sans.org/diary.php?date=2005-09-19; classtype:trojan-activity; sid: 2002373; rev:1;)