alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/saolei CnC Host Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"|2f|shell|2f 3f|par|3d|"; startswith; fast_pattern; content:"&val="; distance:0; content:"LS0"; distance:0; http.header_names; content:!"|0d 0a|User-Agent|0d 0a|"; nocase; content:!"|0d 0a|Referer|0d 0a|"; nocase; reference:md5,c8e6cd1fb6f5dfe1ab548024a7f67043; classtype:trojan-activity; sid:2054616; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2024_07_19, deployment Perimeter, malware_family Win32_saolei, confidence High, signature_severity Critical, tag c2, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_07_19, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)