alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MOBILE_MALWARE Android Vultr Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/grpc.Rpc/Registration"; fast_pattern; isdataat:!1,relative; http.user_agent; content:"grpc-java-okhttp/"; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; reference:url,www.threatfabric.com/blogs/vultur-v-for-vnc.html; classtype:command-and-control; sid:2033730; rev:3; metadata:attack_target Mobile_Client, created_at 2021_08_13, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_21, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)