alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"MALWARE [PTsecurity] Dridex/Feodo SSL pkt checker #2.1"; flow:established, to_client; content:"|17 03 01 01 60|"; depth:5; stream_size:server, <,2257; stream_size:client, <,10263; stream_size:client, >,0; stream_size:server, >,0; flowbits:isset, FB313831_1; flowbits:unset, FB313831_1; threshold:type limit, track by_src, count 1, seconds 300; classtype:trojan-activity; metadata:created_at 2017_8_1; reference:url, github.com/ptresearch/AttackDetection; sid:11001686; rev:1;)