Cisco Umbrella - Connection to Unpopular Website Detected

Description

'Detects first connection to an unpopular website (possible malicious payload delivery).'

Query · kql

let domain_lookBack= 14d;
let timeframe = 1d;
let top_million_list = Cisco_Umbrella
| where EventType == "proxylogs"
| where TimeGenerated > ago(domain_lookBack) and TimeGenerated < ago(timeframe)
| extend Hostname = parse_url(UrlOriginal)["Host"]
| summarize count() by tostring(Hostname)
| top 1000000 by count_
| summarize make_list(Hostname);
Cisco_Umbrella
| where EventType == "proxylogs"
| where TimeGenerated > ago(timeframe)
| extend Hostname = parse_url(UrlOriginal)["Host"]
| where Hostname !in (top_million_list)
| extend Message = "Connect to unpopular website (possible malicious payload delivery)"
| project Message, SrcIpAddr, DstIpAddr,UrlOriginal, TimeGenerated
Raw source Cisco Umbrella - Connection to Unpopular Website Detected · KQL
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Published by Azure/Azure-Sentinel ↗, licensed under MIT ↗. Reproduced here unmodified. 
id: 75297f62-10a8-4fc1-9b2a-12f25c6f05a7
name: Cisco Umbrella - Connection to Unpopular Website Detected
description: |
  'Detects first connection to an unpopular website (possible malicious payload delivery).'
severity: Medium
requiredDataConnectors:
  - connectorId: CiscoUmbrellaDataConnector
    dataTypes:
      - Cisco_Umbrella_proxy_CL
queryFrequency: 1d
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
query: |
  let domain_lookBack= 14d;
  let timeframe = 1d;
  let top_million_list = Cisco_Umbrella
  | where EventType == "proxylogs"
  | where TimeGenerated > ago(domain_lookBack) and TimeGenerated < ago(timeframe)
  | extend Hostname = parse_url(UrlOriginal)["Host"]
  | summarize count() by tostring(Hostname)
  | top 1000000 by count_
  | summarize make_list(Hostname);
  Cisco_Umbrella
  | where EventType == "proxylogs"
  | where TimeGenerated > ago(timeframe)
  | extend Hostname = parse_url(UrlOriginal)["Host"]
  | where Hostname !in (top_million_list)
  | extend Message = "Connect to unpopular website (possible malicious payload delivery)"
  | 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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