alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Win32/Frosparf.B Downloading Hosts File"; flow:established,from_server; file_data; content:"9.9.9.9 "; within:8; pcre:"/^(?:[a-zA-Z0-9\x2d\x5f]{1,63}\.)+?[a-zA-Z0-9\x2d\x5f]{1,63}[\r\n]*?9\.9\.9\.9\s+?(?:[a-zA-Z0-9\_\-]{1,63}\.)+?[a-zA-Z0-9\x2d\x5f]{1,63}[\r\n]/R"; reference:md5,4ad55877464aa92e49231d913d00eb69; classtype:trojan-activity; sid:2019142; rev:2; metadata:created_at 2014_09_09, malware_family Win32_Frosparf_B, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)