alert tcp any [21,22,23,25,53,80,443,8080] -> any !3389 (msg:"ET POLICY Tunneled RDP msts Handshake"; dsize:<65; content:"|03 00 00|"; depth:3; content:"|e0|"; distance:2; within:1; content:"Cookie|3a 20|mstshash="; distance:5; within:17; reference:url,www.fireeye.com/blog/threat-research/2019/01/bypassing-network-restrictions-through-rdp-tunneling.html; classtype:bad-unknown; sid:2027192; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_04_11, deployment Perimeter, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)