alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed upStage Proxy CnC Domain (nova .smshero .ai) in TLS SNI"; flow:established,to_server; tls.sni; bsize:15; content:"nova.smshero.ai"; fast_pattern; reference:url,www.malwarebytes.com/blog/threat-intel/2026/02/fake-7-zip-downloads-are-turning-home-pcs-into-proxy-nodes; reference:url,blog.lukeacha.com/2026/01/beware-of-fake-7zip-installer-upstage.html; classtype:domain-c2; sid:2067624; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2026_02_11, deployment Perimeter, malware_family upStage, malware_family Residential_Proxy, performance_impact Low, confidence High, signature_severity Major, updated_at 2026_02_11, mitre_tactic_id TA0042, mitre_tactic_name Resource_Development, mitre_technique_id T1583, mitre_technique_name Acquire_Infrastructure;)