alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"MALWARE [PTsecurity] TrickBot.Spy SSL connection pkt checker #0"; flow:established, to_server; content:"|1703|"; depth:2; byte_test:2, >=,240, 1, relative; byte_test:2, <=,288, 1, relative; stream_size:server, >,1278; stream_size:server, <,3797; stream_size:client, >,374; stream_size:client, <,1657; flowbits:noalert; flowbits:isset, FB566923_; flowbits:unset, FB566923_; flowbits:set, FB566923_0; classtype:trojan-activity; metadata:created_at 2018_05_11; reference:url, github.com/ptresearch/AttackDetection; sid:11002939; rev:1;)