alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/BlackLotus CnC Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.user_agent; content:"Mozilla/5.0"; bsize:11; http.request_body; content:"checkin="; depth:8; fast_pattern; nocase; http.header_names; content:!"Referer"; reference:url,welivesecurity.com/2023/03/01/blacklotus-uefi-bootkit-myth-confirmed; classtype:command-and-control; sid:2044419; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_03_01, deployment Perimeter, deployment SSLDecrypt, malware_family Win32_BlackLotus, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_01;)