alert tcp $EXTERNAL_NET [53, 443] -> $HOME_NET any (msg:"MALWARE [PTsecurity] Bunitu.Proxy pkt checker #1"; flow:established, to_client; dsize:50; content:"|00|"; offset:1; depth:1; stream_size:server, =,51; stream_size:client, =,15; flowbits:noalert; flowbits:isset, FB70820_0; flowbits:unset, FB70820_0; flowbits:set, FB70820_1; classtype:trojan-activity; metadata:created_at 2017_8_26; reference:url, github.com/ptresearch/AttackDetection; sid:11000340; rev:4;)