alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed RMM Domain in TLS SNI (servicedesk .itarian .com)"; flow:established,to_server; tls.sni; bsize:23; content:"servicedesk.itarian.com"; fast_pattern; reference:url,help.itarian.com/topic-459-1-1005-14776-Appendix-1b---Endpoint-Manager-Services---IP-Nos,-Host-Names-and-Port-Details---US-Customers.html; classtype:misc-activity; sid:2064344; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, affected_product Windows_8, affected_product Windows_10, affected_product ITarian, attack_target Client_and_Server, created_at 2025_09_04, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag RAT, tag RemoteAccessTool, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_04, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1219, mitre_technique_name Remote_Access_Software;)