alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO AmanVPN Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/CLogin?key="; startswith; fast_pattern; pcre:"/^[A-Za-z0-9+/=]{730,}/R"; http.user_agent; content:"Lingjiang"; bsize:9; http.header_names; content:!"Referer"; content:"|0d 0a|Host|0d 0a|User-Agent|0d 0a|Accept-Encoding|0d 0a 0d 0a|"; threshold:type limit, count 1, seconds 600, track by_src; reference:md5,185a0a1a16f93c8e43cdb2955d4c64c4; classtype:misc-activity; sid:2036976; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_06_13, deployment Perimeter, malware_family AmanVPN, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_05_09;)