alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT39/Chafer Payload - CnC Checkin M1"; flow:established,to_server; http.method; content:"BITS_POST"; http.uri; content:"/googleyou_"; startswith; fast_pattern; http.header_names; content:"BITS-"; classtype:command-and-control; sid:2030915; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, created_at 2020_09_29, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_29;)