Cisco Umbrella - Empty User Agent Detected

Description

'Rule helps to detect empty and unusual user agent indicating web browsing activity by an unusual process other than a web browser.'

Query · kql

let timeframe = 15m;
Cisco_Umbrella
| where EventType == "proxylogs"
| where TimeGenerated > ago(timeframe)
| where HttpUserAgentOriginal == ''
| extend Message = "Empty User Agent"
| project Message, SrcIpAddr, DstIpAddr, UrlOriginal, TimeGenerated
Raw source Cisco Umbrella - Empty User Agent Detected · KQL
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Published by Azure/Azure-Sentinel ↗, licensed under MIT ↗. Reproduced here unmodified. 
id: 2b328487-162d-4034-b472-59f1d53684a1
name: Cisco Umbrella - Empty User Agent Detected
description: |
  'Rule helps to detect empty and unusual user agent indicating web browsing activity by an unusual process other than a web browser.'
severity: Medium
requiredDataConnectors:
  - connectorId: CiscoUmbrellaDataConnector
    dataTypes:
      - Cisco_Umbrella_proxy_CL
queryFrequency: 15m
queryPeriod: 15m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
query: |
  let timeframe = 15m;
  Cisco_Umbrella
  | where EventType == "proxylogs"
  | where TimeGenerated > ago(timeframe)
  | where HttpUserAgentOriginal == ''
  | extend Message = "Empty User Agent"
  | project Message, SrcIpAddr, DstIpAddr, UrlOriginal, TimeGenerated
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlOriginal
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
version: 1.1.2
kind: Scheduled

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