alert http $EXTERNAL_NET 443 -> $HOME_NET any (msg:"ET EXPLOIT_KIT CottonCastle/Niteris EK Secondary Landing Aug 17 2015"; flow:established,to_client; file.data; content:"fromCharCode"; nocase; content:"charCodeAt"; nocase; content:"fontFamily"; nocase; content:"style"; nocase; content:"language"; nocase; pcre:"/^\s*?=\s*?[\x22\x27]vb[\x22\x27]/Rsi"; content:"^"; pcre:"/^\s*?\w+\s*?\.\s*?charCodeAt/Rsi"; content:"decodeURIComponent"; nocase; fast_pattern; classtype:exploit-kit; sid:2021637; rev:4; metadata:created_at 2015_08_17, confidence High, signature_severity Major, updated_at 2024_03_14;)