alert http $HOME_NET any -> $EXTERNAL_NET [443,7080,8080] (msg:"ET MALWARE W32/Emotet Empty CnC Beacon"; flow:established,to_server; http.start; content:"GET / HTTP/1.1|0d 0a|User-Agent|3a 20|Mozilla/5.0 (compatible|3b 20|MSIE 8.0|3b 20|Windows NT 5.1|3b 20|SLCC1|3b 20|.NET CLR 1.1.4322)|0d 0a|Host|3a|"; depth:111; fast_pattern; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept"; content:!"Cookie|0d 0a|"; reference:md5,627f3572e9c37de307b3511925934fb9; classtype:command-and-control; sid:2035046; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_05_09, deployment Perimeter, malware_family Emotet, confidence High, signature_severity Major, tag c2, updated_at 2020_11_05, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)