alert dns $HOME_NET any -> any any (msg:"ET MALWARE Possible DNS Tunneling Observed"; dns.query; content:".aaaaaaaaaaaa"; fast_pattern; pcre:"/^[abcdefghiklmnopqrstvxyz123456789]{62}\.aaaaaaaaaaaa/"; reference:url,www.welivesecurity.com/wp-content/uploads/2020/06/ESET_InvisiMole.pdf; classtype:trojan-activity; sid:2030352; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_06_18, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_06_18;)