alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE SainboxRAT CnC Config Request"; flow:established,to_server; flowbits:set,ET.sainbox.config; http.uri; content:".txt"; endswith; http.host; bsize:26; content:"gist.githubusercontent.com"; fast_pattern; http.user_agent; bsize:11; content:"Mozilla/5.0"; http.header_names; bsize:37; content:"|0d 0a|user-agent|0d 0a|host|0d 0a|cache-control|0d 0a 0d 0a|"; nocase; classtype:trojan-activity; sid:2069282; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_05_14, deployment Perimeter, deployment SSLDecrypt, malware_family Sainbox, confidence Medium, signature_severity Major, tag c2, updated_at 2026_05_14, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)