alert dns $HOME_NET any -> any any (msg:"ET MALWARE Known IoT Malware Domain"; dns.query; content:"ntp.gtpnet.ir"; depth:13; nocase; endswith; fast_pattern; reference:url,blog.netlab.360.com/a-new-threat-an-iot-botnet-scanning-internet-on-port-81-en/; classtype:trojan-activity; sid:2024244; rev:5; metadata:attack_target IoT, created_at 2017_04_25, deployment Perimeter, confidence High, signature_severity Minor, updated_at 2020_09_17;)