alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE DarkHotel Downloader CnC Beacon 1"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"2.php?jpg="; fast_pattern; content:!"&"; distance:0; pcre:"/\/[a-z]+2\.php\?jpg=[^&]+$/"; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; reference:url,labs.bitdefender.com/2017/07/inexsmar-an-unusual-darkhotel-campaign/; classtype:targeted-activity; sid:2024482; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_07_20, deployment Perimeter, malware_family DarkHotel, confidence High, signature_severity Major, tag Targeted, tag APT, tag DarkHotel, tag c2, updated_at 2020_08_10, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)