alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Throwback CnC Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.header_names; content:"|0d 0a|Connection|0d 0a|Pragma|0d 0a|Content-Type|0d 0a|User-Agent|0d 0a|Content-Length|0d 0a|Host|0d 0a 0d 0a|"; endswith; content:!"Referer"; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.request_body; content:"pd="; fast_pattern; startswith; pcre:"/^(?:[A-Za-z0-9~\+\/]{4})*(?:[A-Za-z0-9~\+\/]{2}==|[A-Za-z0-9~\+\/]{3}=|[A-Za-z0-9~\+\/]{4})$/R"; reference:url,github.com/silentbreaksec/Throwback; classtype:trojan-activity; sid:2036590; rev:3; metadata:attack_target Client_Endpoint, created_at 2022_05_12, deployment Perimeter, malware_family Throwback, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_02;)