Cisco Umbrella - Empty User Agent Detected

Back


Id	2b328487-162d-4034-b472-59f1d53684a1
Rulename	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
Tactics	CommandAndControl
Required data connectors	CiscoUmbrellaDataConnector
Kind	Scheduled
Query frequency	15m
Query period	15m
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/CiscoUmbrella/CiscoUmbrellaEmptyUserAgentDetected.yaml
Version	1.1.2
Arm template	2b328487-162d-4034-b472-59f1d53684a1.json

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

YAML

queryPeriod: 15m
kind: Scheduled
entityMappings:
- entityType: URL
  fieldMappings:
  - identifier: Url
    columnName: UrlOriginal
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SrcIpAddr
requiredDataConnectors:
- connectorId: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_proxy_CL
description: |
    'Rule helps to detect empty and unusual user agent indicating web browsing activity by an unusual process other than a web browser.'
queryFrequency: 15m
triggerOperator: gt
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  
name: Cisco Umbrella - Empty User Agent Detected
id: 2b328487-162d-4034-b472-59f1d53684a1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/CiscoUmbrella/CiscoUmbrellaEmptyUserAgentDetected.yaml
severity: Medium
version: 1.1.2
triggerThreshold: 0
tactics:
- CommandAndControl

ARM