alert dns $HOME_NET any -> any any (msg:"ET MOBILE_MALWARE NSO Group CnC Domain in DNS Lookup"; dns.query; content:"oldgoldcities.com"; nocase; bsize:17; reference:url,context-cdn.washingtonpost.com/notes/prod/default/documents/bf5edf35-5672-49fa-aca1-edefadff683f/note/8ef25c0d-fee9-416a-b7f9-e0a4dedc66f2.pdf; reference:url,twitter.com/jsrailton/status/1253526716460535808; classtype:command-and-control; sid:2030026; rev:2; metadata:attack_target Mobile_Client, created_at 2020_04_24, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_17;)