alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Black KingDom Ransomware Related Activity"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/vpn-service/"; startswith; content:"crunchyroll-vpn"; endswith; fast_pattern; pcre:"/^\/vpn-service\/[a-z]{15}\/crunchyroll-vpn$/"; reference:url,news.sophos.com/en-us/2021/03/23/black-kingdom/; classtype:trojan-activity; sid:2032331; rev:2; metadata:attack_target Client_Endpoint, created_at 2021_03_25, deployment Perimeter, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_03_25, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)