alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Xtrat.A Checkin"; flow:established,to_server; http.uri; content:".functions"; fast_pattern; endswith; pcre:"/^\/\d+\.functions$/"; http.host; content:!"microsoft.com"; http.header_names; content:!"Referer"; reference:md5,f45b1b82c849fbbea3374ae7e9200092; classtype:command-and-control; sid:2016275; rev:12; metadata:created_at 2011_12_13, malware_family Win32_Xtrat_A, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_14;)