Excessive NXDOMAIN DNS Queries

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Id	b8266f81-2715-41a6-9062-42486cbc9c73
Rulename	Excessive NXDOMAIN DNS Queries
Description	This creates an incident in the event a client generates excessive amounts of DNS queries for non-existent domains.
Severity	Medium
Tactics	CommandAndControl
Techniques	T1568 T1008
Required data connectors	SyslogAma
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Infoblox NIOS/Analytic Rules/ExcessiveNXDOMAINDNSQueries.yaml
Version	1.0.5
Arm template	b8266f81-2715-41a6-9062-42486cbc9c73.json

KQL

let threshold = 200;
Infoblox_dnsclient
| where isnotempty(DnsResponseCode)
| where DnsResponseCode =~ "NXDOMAIN"
| summarize count() by SrcIpAddr, bin(TimeGenerated,15m)
| where count_ > threshold
| join kind=inner (Infoblox_dnsclient
    | where isnotempty(DnsResponseCode)
    | where DnsResponseCode =~ "NXDOMAIN"
    ) on SrcIpAddr

YAML

query: |
  let threshold = 200;
  Infoblox_dnsclient
  | where isnotempty(DnsResponseCode)
  | where DnsResponseCode =~ "NXDOMAIN"
  | summarize count() by SrcIpAddr, bin(TimeGenerated,15m)
  | where count_ > threshold
  | join kind=inner (Infoblox_dnsclient
      | where isnotempty(DnsResponseCode)
      | where DnsResponseCode =~ "NXDOMAIN"
      ) on SrcIpAddr  
kind: Scheduled
triggerThreshold: 0
entityMappings:
- fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
  entityType: IP
description: |
    'This creates an incident in the event a client generates excessive amounts of DNS queries for non-existent domains.'
version: 1.0.5
id: b8266f81-2715-41a6-9062-42486cbc9c73
relevantTechniques:
- T1568
- T1008
queryPeriod: 1h
queryFrequency: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Infoblox NIOS/Analytic Rules/ExcessiveNXDOMAINDNSQueries.yaml
tactics:
- CommandAndControl
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
  datatypes:
  - Syslog
name: Excessive NXDOMAIN DNS Queries
triggerOperator: gt

ARM