alert http $HTTP_SERVERS any -> $EXTERNAL_NET any (msg:"GPL ATTACK_RESPONSE Invalid URL"; flow:from_server,established; content:"Invalid URL"; nocase; reference:url,www.microsoft.com/technet/security/bulletin/MS00-063.mspx; classtype:attempted-recon; sid:2101200; rev:12; metadata:created_at 2010_09_23, confidence Medium, signature_severity Informational, updated_at 2019_07_26;)