alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Nuclear EK CVE-2013-2551 URI Struct Sept 17 2014"; flow:established,to_server; content:"/14"; http_uri; content:".htm"; http_uri; distance:8; within:4; pcre:"/^\/[a-z0-9]+?(?:\/\d)?\/14\d{8}\.htm$/U"; pcre:"/^Referer\x3a[^\r\n]+?\/[a-f0-9A-Z\_\-]{14,}\.html(?:\x3a\d{1,5})?\r$/Hm"; flowbits:set,et.exploitkitlanding; classtype:exploit-kit; sid:2019189; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2014_09_18, deployment Perimeter, malware_family Nuclear, confidence High, signature_severity Critical, tag Exploit_Kit, tag Nuclear, tag CISA_KEV, updated_at 2019_07_26;)