alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE MuddyWater APT Related Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:!".asp"; content:!".htm"; content:!".php"; http.header; content:"|0d 0a|CharSet|3a 20|UTF-8|0d 0a|"; fast_pattern; http.request_body; content:"c="; startswith; http.header_names; content:!"Referer"; reference:md5,69ff29b86ab5444197aeb0cf5eba0967; reference:url,blog.talosintelligence.com/2022/03/iranian-supergroup-muddywater.html; classtype:trojan-activity; sid:2035425; rev:3; metadata:attack_target Client_Endpoint, created_at 2022_03_10, deployment Perimeter, malware_family MuddyWater, malware_family TA450, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_05_02;)