alert udp $HOME_NET any -> $EXTERNAL_NET [53,4499,8000] (msg:"ET MALWARE nspx30 Backdoor Trigger Response Observed"; dsize:1000<>1500; content:"|fe ad 01 00|"; startswith; content:"|00 01 00 00 00 00 00|"; within:7; content:"|09|microsoft|03|com"; nocase; distance:1; within:14; content:"|00 00 01 00 01 aa 9d 9d 9d 9d 9d 9d a5 aa|"; fast_pattern; within:14; reference:url,www.welivesecurity.com/en/eset-research/nspx30-sophisticated-aitm-enabled-implant-evolving-since-2005/; classtype:trojan-activity; sid:2050497; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, created_at 2024_01_25, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_01_25; target:src_ip;)