alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32.Rioselx.A Checkin"; flow:established,to_server; http.uri; content:"/access.php"; fast_pattern; http.user_agent; content:!"Mozilla"; within:7; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})/"; http.content_type; content:"application/x-www-form-urlencoded"; startswith; http.header_names; content:!"Referer"; content:!"Accept"; content:"Content-Length|0d 0a|"; reference:md5,3eb94c397a395f24b84297593f69710a; classtype:command-and-control; sid:2021442; rev:6; metadata:created_at 2015_07_20, signature_severity Major, updated_at 2020_05_29;)