alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET EXPLOIT_KIT Nuclear EK Landing Apr 03 2015"; flow:established,to_client; http.server; content:"nginx"; startswith; file.data; content:"return eval"; fast_pattern; content:"replace"; pcre:"/^\s*?\x28\s*?\x22\s\x22\s*?,\s*?\x22Q(?:\x22\s*?\+\s*?\x22)?Q\x22/Rs"; classtype:exploit-kit; sid:2020842; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2015_04_04, deployment Perimeter, malware_family Nuclear, confidence High, signature_severity Critical, tag Exploit_Kit, tag Nuclear, updated_at 2024_03_03;)