alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING WebDAV Traffic to Cloudflare Tunneling Service (.trycloudflare .com)"; flow:established,to_server; http.user_agent; content:"Microsoft-WebDAV-MiniRedir"; http.host; content:".trycloudflare.com"; endswith; fast_pattern; threshold:type limit,count 1,seconds 300,track by_src; classtype:misc-activity; sid:2065648; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_11_04, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_11_04, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1568, mitre_technique_name Dynamic_Resolution; target:src_ip;)