Rule History

alert http $HOME_NET any -> $EXTERNAL_NET [80,443,4143,7080,8080] (msg:"ET MALWARE Win32/Emotet CnC Activity M12 (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:!"."; content:!"&"; content:!"-"; content:!"?"; content:"/"; endswith; http.header_names; content:"|0d 0a|Connection|0d 0a|Content-Type|0d 0a|Content-Length|0d 0a|Host|0d 0a 0d 0a|"; startswith; fast_pattern; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.request_body; content:"="; depth:17; content:!"rtype="; depth:6; pcre:"/^[A-Za-z]{2,16}=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})/"; content:"&"; within:4; http.content_len; byte_test:0,<,2048,0,string,dec; classtype:trojan-activity; sid:2043308; rev:7; metadata:attack_target Client_Endpoint, created_at 2023_01_17, deployment Perimeter, deployment SSLDecrypt, malware_family Emotet, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_16, reviewed_at 2023_11_14; target:src_ip;)