alert http $HTTP_SERVERS any -> $EXTERNAL_NET any (msg:"ET WEB_SERVER China Chopper WebShell Observed Outbound"; flow:established,from_server; http.stat_code; content:"200"; file.data; content:"|3c 25 40 20|Page|20|Language=|22|Jscript|22 25 3e 3c 25|eval|28|"; fast_pattern; content:"FromBase64String"; distance:0; nocase; content:"|25 3e|"; distance:0; classtype:trojan-activity; sid:2027393; rev:2; metadata:affected_product Web_Server_Applications, attack_target Server, created_at 2019_05_29, deployment Perimeter, performance_impact Low, signature_severity Major, updated_at 2020_08_31;)