alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed AsyncRAT CnC Domain (wuwu6 .cfd in TLS SNI)"; flow:established,to_server; tls.sni; bsize:9; content:"wuwu6.cfd"; fast_pattern; reference:url,securelist.com/godrat/117119/; reference:url,malpedia.caad.fkie.fraunhofer.de/details/win.asyncrat; classtype:trojan-activity; sid:2064285; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2025_09_03, deployment Perimeter, malware_family AsyncRAT, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_03, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)