alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Bamital Connectivity Check"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/ncsi.txt"; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept-"; content:"|0d 0a|Host|0d 0a|"; depth:8; http.user_agent; content:"Mozilla/5.0 (compatible|3b| MSIE 9.0|3b| Windows NT 6.1|3b| WOW64|3b| Trident/5.0)"; fast_pattern; classtype:trojan-activity; sid:2019754; rev:4; metadata:created_at 2014_11_20, signature_severity Major, updated_at 2020_05_13;)