alert dns any any -> any any (msg:"ET MALWARE Suspected Sliver DNS CnC"; content:"|00 10 00 01|"; isdataat:!1,relative; dns.query; content:"_"; startswith; pcre:"/^[a-z0-9_]{6}[^a-z0-9_]/R"; content:"_domainkey"; distance:8; fast_pattern; reference:url,github.com/BishopFox/sliver; classtype:trojan-activity; sid:2032936; rev:2; metadata:attack_target Client_Endpoint, created_at 2021_05_10, deployment Perimeter, malware_family Sliver, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_05_19;)