alert dns $HOME_NET any -> any any (msg:"ET MALWARE PolyglotDuke Domain Observed"; dns.query; content:"sistemikan.com"; nocase; endswith; reference:url,www.welivesecurity.com/wp-content/uploads/2019/10/ESET_Operation_Ghost_Dukes.pdf; classtype:trojan-activity; sid:2028853; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_10_17, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_20;)