alert dns $HOME_NET any -> any any (msg:"ET MALWARE Possible PlugX DNS Lookup (operaa.net)"; dns_query; content:"operaa.net"; depth:10; nocase; endswith; fast_pattern; reference:url,volexity.com/blog/?p=179; classtype:trojan-activity; sid:2021936; rev:4; metadata:created_at 2015_10_08, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_09_28;)