alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"ET MALWARE BB Trojan Communication Protocol detected"; flow:established,to_server; content:"|01 00 00 00|"; offset:4; depth:4; content:"|01 04 01 00 00|"; distance:8; within:5; reference:url,www.commandfive.com/papers/C5_APT_C2InTheFifthDomain.pdf; classtype:trojan-activity; sid:2014227; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, tls_state plaintext, created_at 2012_02_14, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_12_05; target:src_ip;)