alert dns $HOME_NET any -> any any (msg:"ET MALWARE [Fireeye] Observed SUNBURST DGA Request"; dns.query; content:".appsync-api."; nocase; content:".avsvmcloud.com"; distance:9; within:15; endswith; nocase; fast_pattern; pcre:"/^[a-z0-9]+\.appsync-api\.(?:eu|us)-(?:ea|we)st-[12]\.avsvmcloud\.com$/"; reference:url,www.fireeye.com/blog/threat-research/2020/12/evasive-attacker-leverages-solarwinds-supply-chain-compromises-with-sunburst-backdoor.html; classtype:trojan-activity; sid:2031359; rev:3; metadata:attack_target Client_Endpoint, created_at 2020_12_14, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_12_16;)