alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Suspected Kimsuky Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.user_agent; content:!"Linux"; content:!"Android"; http.request_body; content:"page="; startswith; fast_pattern; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R"; http.header_names; content:!"Referer"; reference:md5,4480e09dbc1514f231ee86110a649965; reference:url,twitter.com/StopMalvertisin/status/1669379332547186690; classtype:trojan-activity; sid:2046617; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_06_22, deployment Perimeter, performance_impact Moderate, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_06_22; target:src_ip;)