alert http $HTTP_SERVERS any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible Outbound WebShell GIF"; flow:established,from_server; http.stat_code; content:"200"; file.data; content:"GIF89a"; depth:6; content:"<%eval|20|request|28 22|"; distance:0; fast_pattern; classtype:trojan-activity; sid:2027738; 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 2020_09_14;)