alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Variant.Zusy.402698 Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".php?serial="; pcre:"/\.php\?serial=[a-z0-9]{16}/U"; http.user_agent; content:"Some USER-AGENT"; bsize:15; fast_pattern; http.header_names; content:!"Referer"; reference:md5,8b9464c10764e08d5939d149dfa451b4; classtype:trojan-activity; sid:2035041; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_02_02, deployment Perimeter, deprecation_reason Age, malware_family Win32_Variant_Zusy_402698, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_12_02, reviewed_at 2024_12_02;)