alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/StoredBt.A Activity"; flow:to_server,established; http.uri; content:".php?a1="; fast_pattern; pcre:"/\.php\?a1=\d+&a2=(?:[0-9A-Fa-f]{2}-[0-9A-Fa-f]{2}-[0-9A-Fa-f]{2}-[0-9A-Fa-f]{2}-[0-9A-Fa-f]{2}-[0-9A-Fa-f]{2}|(?:[A-Za-z0-9\+\/]{4})*(?:[A-Za-z0-9\+\/]{2}==|[A-Za-z0-9\+\/]{3}=|[A-Za-z0-9\+\/]{4}))(?:&a\d+=[^&]+)+$/"; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept-"; reference:md5,e8e9eb1cd4be7ab27743887be2aa28e9; classtype:trojan-activity; sid:2018074; rev:4; metadata:created_at 2014_02_05, malware_family Win32_StoredBt_A, signature_severity Major, updated_at 2020_09_22;)