alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed TransferLoader Domain (mainstomp .cloud) in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".mainstomp.cloud"; endswith; fast_pattern; reference:url,www.zscaler.com/blogs/security-research/technical-analysis-transferloader; classtype:domain-c2; sid:2063146; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2025_06_23, deployment Perimeter, malware_family TransferLoader, performance_impact Low, confidence High, signature_severity Major, updated_at 2025_06_23, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1567, mitre_technique_name Exfiltration_Over_Web_Service;)