alert dns $HOME_NET any -> any any (msg:"ET MALWARE Cryptowall .onion Proxy Domain"; dns.query; content:"3wzn5p2yiumh7akj"; startswith; nocase; reference:url,www.bleepingcomputer.com/news/security/cryptowall-4-0-released-with-new-features-such-as-encrypted-file-names; classtype:trojan-activity; sid:2022048; rev:4; metadata:created_at 2015_11_09, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_12;)