alert http $EXTERNAL_NET [443,7080,8080,80] -> $HOME_NET any (msg:"ET MALWARE W32/Emotet.v4 Checkin Fake 404 Payload Response"; flow:established,from_server; content:"404"; http_stat_code; http_content_type; content:"text/html"; http_content_len; byte_test:0,<=,999999,0,string,dec; byte_test:0,>,99999,0,string,dec; file_data; content:!"<html"; nocase; depth:1024; pcre:"/^[\x20-\x7e\r\n]{0,20}[^\x20-\x7e\r\n][\x20-\x7e\r\n]{0,20}[^\x20-\x7e\r\n][\x20-\x7e\r\n]{0,20}[^\x20-\x7e\r\n]/si"; reference:md5,dacdcd451204265ad6f44ef99db1f371; classtype:command-and-control; sid:2035065; rev:1; metadata:created_at 2022_02_03, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_03;)