alert tcp $HOME_NET any -> $EXTERNAL_NET !$HTTP_PORTS (msg:"ET MALWARE [PTsecurity] Ursnif Socks Proxy Check-in"; flow:established,to_server; stream_size:server,=,1; content:"|2d|"; offset:8; depth:1; content:"|2d|"; distance:4; within:1; content:"|2d|"; distance:4; within:1; content:"|2d|"; distance:4; within:1; content:"|2d30|"; distance:12; within:2; content:"|0000 0000 0000 0000 0000 0000|"; distance:1; within:12; fast_pattern; pcre:"/^[0-9A-Z]{8}-[0-9A-Z]{4}-[0-9A-Z]{4}-[0-9A-Z]{4}-[0-9]{12}-0[0-9]{1}/"; flowbits:set,PT.UrsnifProxy; flowbits:noalert; classtype:trojan-activity; sid:2025444; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_03_28, deployment Perimeter, malware_family ursnif, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)