alert dns $HOME_NET any -> any any (msg:"ET INFO Suspicious Outbound SIG DNS Query"; content:"|00 00 18 00 01|"; fast_pattern; dns.query; pcre:"/^\d/"; classtype:bad-unknown; sid:2030547; rev:2; metadata:created_at 2020_07_16, performance_impact Significant, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_17;)