alert dns $HOME_NET any -> any any (msg:"ET MALWARE ASNAROK Related Domain in DNS Lookup"; dns.query; content:"sophosfirewallupdate.com"; nocase; bsize:24; reference:url,news.sophos.com/en-us/2020/04/26/asnarok/; classtype:trojan-activity; sid:2030031; rev:2; metadata:attack_target Networking_Equipment, created_at 2020_04_27, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_17;)