alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET RETIRED SAFIB Assistant Remote Administration Tool CnC Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/api/exec"; fast_pattern; bsize:9; http.header_names; content:"Host|0d 0a|Content-Length|0d 0a 0d 0a|"; http.request_body; content:"|31 00 00|"; offset:1; content:"|01 00 00|"; distance:1; reference:md5,7a40cf7374eb22988a32f47a433a76fe; classtype:misc-activity; sid:2038600; rev:2; metadata:attack_target Client_Endpoint, created_at 2022_08_23, deployment Perimeter, deployment SSLDecrypt, former_category INFO, performance_impact Low, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_09_17, reviewed_at 2024_09_17;)