alert tcp $EXTERNAL_NET [20000:] -> $HOME_NET any (msg:"MALWARE [PTsecurity] Bayrob detected "; flow:established, to_client; flowbits:isset,PT.Bayrob0; dsize:2; flags:PA; stream_size:server,=,3; stream_size:client,<,400; flowbits:unset,PT.Bayrob0; classtype:trojan-activity; metadata:created_at 2017_6_2; reference:url, blog.fortinet.com/2016/07/27/bayrob-an-ancient-evil-awakens-ii; reference:url, github.com/ptresearch/AttackDetection; sid:11001394; rev:2;)