alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Braincrypt Ransomware CnC Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".php?uuid="; fast_pattern; pcre:"/\.php\?uuid=[a-z0-9]{32}$/i"; http.user_agent; content:"Go-http-client/"; startswith; http.header_names; content:!"Accept|0d 0a|"; content:!"Referer|0d 0a|"; reference:md5,6b938ca31a55e743112ab34dc540a076; classtype:command-and-control; sid:2023675; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_12_20, deployment Perimeter, malware_family Ransomware, malware_family Braincrypt, signature_severity Major, tag Ransomware, updated_at 2020_10_07, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)