alert http $HOME_NET any -> $EXTERNAL_NET 443 (msg:"ET DELETED Unknown Web Backdoor Keep-Alive"; flow:established,to_server; urilen:13; content:"POST"; http_method; nocase; content:"/bbs/info.asp"; http_uri; classtype:trojan-activity; sid:2012250; rev:3; metadata:created_at 2011_02_02, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)