alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE MSIL/Unk.HT-Based Ransomware CnC Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; http.request_body; content:"hostname=csharp-"; depth:16; fast_pattern; content:"&enckey="; distance:0; http.header_names; content:!"User-Agent|0d 0a|"; content:!"Referer|0d 0a|"; reference:md5,2aa11c090fd0737e52cd532418c1211e; classtype:command-and-control; sid:2024352; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_06_06, deployment Perimeter, malware_family Ransomware, malware_family Hidden_Tear, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_06, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)