alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"MALWARE [PTsecurity] Babylon RAT pkt checker #0"; flow:established, to_client; dsize:4; content:"|FF|"; offset:1; depth:1; stream_size:server, >,0; stream_size:server, <,30; stream_size:client, >,0; stream_size:client, <,160; flowbits:noalert; flowbits:set, FB322496_0; classtype:trojan-activity; metadata:created_at 2017_8_15; reference:url, github.com/ptresearch/AttackDetection; sid:11001783; rev:1;)