title: Possible DNS Tunneling id: 1ec4b281-aa65-46a2-bdae-5fd830ed914e status: experimental description: Normally, DNS logs contain a limited amount of different dns queries for a single domain. This rule detects a high amount of queries for a single domain, which can be an indicator that DNS is used to transfer data. author: Patrick Bareiss date: 2019/04/07 modified: 2020/08/27 references: - https://zeltser.com/c2-dns-tunneling/ - https://patrick-bareiss.com/detect-c2-traffic-over-dns-using-sigma/ logsource: category: dns detection: selection: parent_domain: '*' condition: selection | count(dns_query) by parent_domain > 1000 falsepositives: - Valid software, which uses dns for transferring data level: high tags: - attack.command_and_control - attack.t1071 # an old one - attack.t1071.004 - attack.exfiltration - attack.t1048 # an old one - attack.t1048.003