alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Red Leaves HTTP CnC Beacon (APT10 implant)"; flow:established,to_server; threshold:type limit, track by_src, count 1, seconds 600; http.method; content:"POST"; http.uri; content:"/index.php"; endswith; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(?:\x3a\d{1,5})?$/"; http.request_body; pcre:"/^[\x20-\x7e\r\n]{0,28}[^\x20-\x7e\r\n]/s"; http.accept; content:"*/*"; depth:3; endswith; http.connection; content:"Keep-Alive"; depth:10; endswith; http.start; content:"dex.php|20|HTTP/1.1|0d 0a|Co"; fast_pattern; http.header_names; content:!"Content-Type|0d 0a|"; content:!"User-Agent|0d 0a|"; content:!"Accept-"; content:!"Referer|0d 0a|"; reference:url,github.com/nccgroup/Cyber-Defence/blob/master/Technical%20Notes/Red%20Leaves/Red%20Leaves%20technical%20note%20v1.0.pdf; reference:url,blog.jpcert.or.jp/2017/04/redleaves---malware-based-on-open-source-rat.html; classtype:targeted-activity; sid:2024175; rev:6; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_04_04, deployment Perimeter, malware_family RedLeaves, malware_family Red_Leaves, confidence High, signature_severity Major, tag APT, tag APT10, tag RedLeaves, tag c2, updated_at 2020_11_05, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)