alert tcp $HOME_NET any -> $EXTERNAL_NET !$HTTP_PORTS (msg:"MALWARE [PTsecurity] Tofsee.bot pkt97 sequence"; flow:established, to_server; dsize:97; flags:PA; stream_size:client,<,300; stream_size:server,=,258; flowbits:noalert; flowbits:isset, PT.Tofsee_1; flowbits:unset, PT.Tofsee_1; flowbits:set, PT.Tofsee_2; classtype:trojan-activity; metadata:created_at 2017_6_2; reference:url, github.com/ptresearch/AttackDetection; sid:11001387; rev:2;)