alert dns $HOME_NET any -> any any (msg:"ET MALWARE TEMP.Periscope APT Domain in DNS Lookup"; dns.query; content:"thyssenkrupp-marinesystems.org"; nocase; fast_pattern; endswith; reference:url,go.recordedfuture.com/hubfs/reports/cta-2018-1113.pdf; classtype:targeted-activity; sid:2026612; rev:4; metadata:attack_target Client_and_Server, created_at 2018_11_15, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag DragonFly, updated_at 2020_09_16;)