alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO ServerChan API Service (SendMessage)"; flow:established,to_server; http.uri; content:".send?title="; fast_pattern; http.host; content:"ftqq.com"; endswith; reference:url,sct.ftqq.com; reference:url,blog.csdn.net/daxiashangxian/article/details/144735604; reference:url,github.com/easychen/serverchan-demo; classtype:misc-activity; sid:2063804; rev:1; metadata:attack_target Client_Endpoint, created_at 2025_07_28, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2025_07_28;)