alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"MALWARE [PTsecurity] Win32/Spy.Ursnif SSL TOR activity"; flow:established, to_server; content:"|1703 01 0220|"; depth:5; fast_pattern; stream_size:server, >,3630; stream_size:server, <,4407; stream_size:client, >,1813; stream_size:client, <,3102; flowbits:isset, FB447357_3; flowbits:unset, FB447357_3; threshold:type limit, track by_src, count 1, seconds 30; classtype:trojan-activity; metadata:created_at 2018_1_17; reference:url, github.com/ptresearch/AttackDetection; sid:11002434; rev:1;)