alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT DRIVEBY Nuclear EK PDF URI Struct March 12 2014"; flow:established,to_server; flowbits:set,et.exploitkitlanding; http.uri; content:".pdf"; fast_pattern; pcre:"/^\/1[34]\d{8}\.pdf$/"; http.header; pcre:"/^Referer\x3a\x20http\x3a\/\/[^\r\n\/]+\/(?:\x3a\d{1,5})?\r$/m"; classtype:exploit-kit; sid:2018258; rev:12; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Any, attack_target Client_Endpoint, created_at 2014_03_12, deployment Perimeter, malware_family Nuclear, confidence High, signature_severity Critical, tag DriveBy, tag Exploit_Kit, tag Nuclear, updated_at 2020_09_23;)