alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"ET EXPLOIT Possible WebShell JPEG Upload"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"|FF D8 FF E0|"; startswith; content:"JFIF"; distance:2; within:4; content:"<%eval|20|request|28 22|"; distance:0; fast_pattern; classtype:attempted-admin; sid:2027737; rev:3; metadata:attack_target Web_Server, created_at 2019_07_22, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag WebShell, updated_at 2024_04_13;)