alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"MALWARE [PTsecurity] Win32/Spy.Ursnif SSL TOR activity pkt checker #1"; flow:established, to_client; content:"|1703 01 0020|"; depth:5; fast_pattern; content:"|1703|"; distance:32; within:2; stream_size:server, >,2414; stream_size:server, <,3863; stream_size:client, >,166; stream_size:client, <,2558; flowbits:noalert; flowbits:isset, FB447357_0; flowbits:unset, FB447357_0; flowbits:set, FB447357_1; classtype:trojan-activity; metadata:created_at 2018_1_17; reference:url, github.com/ptresearch/AttackDetection; sid:11002431; rev:1;)