alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"MALWARE [PTsecurity] Cybergate/Rebhip/Spyrat pkt checker #2"; flow:established, to_client; dsize:3; content:"|0d0a|"; fast_pattern; stream_size:server, >,0; stream_size:client, >,0; stream_size:server, <,5; stream_size:client, <,46; flowbits:isset, FB117960_1; flowbits:unset, FB117960_1; flowbits:set, FB117960_2; flowbits:noalert; classtype:trojan-activity; metadata:created_at 2017_7_13; reference:url, github.com/ptresearch/AttackDetection; sid:11001529; rev:2;)