alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Agent.XST Keepalive"; flow:established,to_server; threshold:type limit, count 1, seconds 60, track by_src; http.method; content:"POST"; http.uri; content:".asp"; http.header; content:"Content-Length|3a 20|2|0d 0a|"; fast_pattern; http.request_body; content:"ok"; depth:2; http.content_type; content:"text/html"; bsize:9; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept|0d 0a|"; reference:md5,d579d7a42ff140952da57264614c37bc; reference:url,asert.arbornetworks.com/wp-content/uploads/2016/01/ASERT-Threat-Intelligence-Brief-Uncovering-the-Seven-Pointed-Dagger.pdf; classtype:trojan-activity; sid:2022363; rev:5; metadata:created_at 2016_01_13, malware_family Win32_Agent_XST, signature_severity Major, updated_at 2020_10_06;)