alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP Win32/BrowseFox.H Checkin 2"; flow:established,to_server; urilen:3; http.method; content:"POST"; http.uri; content:"/rs"; http.request_body; content:"alpha="; fast_pattern; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R"; http.header_names; content:!"User-Agent"; content:!"Accept"; content:!"Referer"; reference:md5,437a5cb57567c2691ce61a700682eab7; classtype:pup-activity; sid:2018899; rev:6; metadata:created_at 2014_07_29, signature_severity Minor, updated_at 2020_08_31;)