alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE CryptoShield Ransomware Checkin"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"id="; depth:3; content:"&numbers=-----"; content:"BEGIN|20|PRIVATE|20|KEY"; fast_pattern; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.header_names; content:!"Referer|0d 0a|"; content:!"User-Agent|0d 0a|"; content:!"Accept"; reference:md5,ef815146b802cfd6a5fb67d1f9267745; classtype:command-and-control; sid:2023814; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_01_31, deployment Perimeter, malware_family Ransomware, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_04, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)