Office 365 - SharePoint File Operation via Previously Unseen IPs

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Id	7460e34e-4c99-47b2-b7c0-c42e339fc586
Rulename	Office 365 - SharePoint File Operation via Previously Unseen IPs
Description	Identifies anomalies using user behavior by setting a threshold for significant changes in file upload/download activities from new IP addresses. It establishes a baseline of typical behavior, compares it to recent activity, and flags deviations exceeding a default threshold of 25.
Severity	Medium
Tactics	Exfiltration
Techniques	T1030
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1d
Query period	14d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/Office 365 - SharePoint_Downloads_byNewIP.yaml
Version	2.0.5
Arm template	7460e34e-4c99-47b2-b7c0-c42e339fc586.json

KQL

let threshold = 0.25;
let szSharePointFileOperation = "SharePointFileOperation";
let szOperations = dynamic(["FileDownloaded", "FileUploaded"]);
let starttime = 14d;
let endtime = 1d;
// Define a baseline of normal user behavior
let userBaseline = EnrichedMicrosoft365AuditLogs
| where TimeGenerated between(ago(starttime)..ago(endtime))
| where RecordType == szSharePointFileOperation
| where Operation in (szOperations)
| extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)
| extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)
| where isnotempty(UserAgent)
| summarize Count = count() by UserId, Operation, Site_Url, ClientIp
| summarize AvgCount = avg(Count) by UserId, Operation, Site_Url, ClientIp;
// Get recent user activity
let recentUserActivity = EnrichedMicrosoft365AuditLogs
| where TimeGenerated > ago(endtime)
| where RecordType == szSharePointFileOperation
| where Operation in (szOperations)
| extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)
| extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)
| where isnotempty(UserAgent)
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIp, ObjectId, Workload, UserAgent;
// Join the baseline and recent activity, and calculate the deviation
let UserBehaviorAnalysis = userBaseline 
| join kind=inner (recentUserActivity) on UserId, Operation, Site_Url, ClientIp
| extend Deviation = abs(RecentCount - AvgCount) / AvgCount;
// Filter for significant deviations
UserBehaviorAnalysis
| where Deviation > threshold
| project StartTimeUtc, EndTimeUtc, UserId, UserType, Operation, ClientIp, Site_Url, ObjectId, Workload, UserAgent, Deviation, Count=RecentCount
| order by Count desc, ClientIp asc, Operation asc, UserId asc
| extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1])

YAML

queryPeriod: 14d
version: 2.0.5
tactics:
- Exfiltration
queryFrequency: 1d
id: 7460e34e-4c99-47b2-b7c0-c42e339fc586
triggerOperator: gt
requiredDataConnectors:
- dataTypes:
  - EnrichedMicrosoft365AuditLogs
  connectorId: AzureActiveDirectory
severity: Medium
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: UserId
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: ClientIp
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Site_Url
    identifier: Url
triggerThreshold: 0
relevantTechniques:
- T1030
query: |
  let threshold = 0.25;
  let szSharePointFileOperation = "SharePointFileOperation";
  let szOperations = dynamic(["FileDownloaded", "FileUploaded"]);
  let starttime = 14d;
  let endtime = 1d;
  // Define a baseline of normal user behavior
  let userBaseline = EnrichedMicrosoft365AuditLogs
  | where TimeGenerated between(ago(starttime)..ago(endtime))
  | where RecordType == szSharePointFileOperation
  | where Operation in (szOperations)
  | extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)
  | extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)
  | where isnotempty(UserAgent)
  | summarize Count = count() by UserId, Operation, Site_Url, ClientIp
  | summarize AvgCount = avg(Count) by UserId, Operation, Site_Url, ClientIp;
  // Get recent user activity
  let recentUserActivity = EnrichedMicrosoft365AuditLogs
  | where TimeGenerated > ago(endtime)
  | where RecordType == szSharePointFileOperation
  | where Operation in (szOperations)
  | extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)
  | extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)
  | where isnotempty(UserAgent)
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIp, ObjectId, Workload, UserAgent;
  // Join the baseline and recent activity, and calculate the deviation
  let UserBehaviorAnalysis = userBaseline 
  | join kind=inner (recentUserActivity) on UserId, Operation, Site_Url, ClientIp
  | extend Deviation = abs(RecentCount - AvgCount) / AvgCount;
  // Filter for significant deviations
  UserBehaviorAnalysis
  | where Deviation > threshold
  | project StartTimeUtc, EndTimeUtc, UserId, UserType, Operation, ClientIp, Site_Url, ObjectId, Workload, UserAgent, Deviation, Count=RecentCount
  | order by Count desc, ClientIp asc, Operation asc, UserId asc
  | extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1])  
kind: Scheduled
name: Office 365 - SharePoint File Operation via Previously Unseen IPs
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/Office 365 - SharePoint_Downloads_byNewIP.yaml
description: |
    Identifies anomalies using user behavior by setting a threshold for significant changes in file upload/download activities from new IP addresses. It establishes a baseline of typical behavior, compares it to recent activity, and flags deviations exceeding a default threshold of 25.
status: Available

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/7460e34e-4c99-47b2-b7c0-c42e339fc586')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/7460e34e-4c99-47b2-b7c0-c42e339fc586')]",
      "properties": {
        "alertRuleTemplateName": "7460e34e-4c99-47b2-b7c0-c42e339fc586",
        "customDetails": null,
        "description": "Identifies anomalies using user behavior by setting a threshold for significant changes in file upload/download activities from new IP addresses. It establishes a baseline of typical behavior, compares it to recent activity, and flags deviations exceeding a default threshold of 25.\n",
        "displayName": "Office 365 - SharePoint File Operation via Previously Unseen IPs",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserId",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "ClientIp",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "Site_Url",
                "identifier": "Url"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/Office 365 - SharePoint_Downloads_byNewIP.yaml",
        "query": "let threshold = 0.25;\nlet szSharePointFileOperation = \"SharePointFileOperation\";\nlet szOperations = dynamic([\"FileDownloaded\", \"FileUploaded\"]);\nlet starttime = 14d;\nlet endtime = 1d;\n// Define a baseline of normal user behavior\nlet userBaseline = EnrichedMicrosoft365AuditLogs\n| where TimeGenerated between(ago(starttime)..ago(endtime))\n| where RecordType == szSharePointFileOperation\n| where Operation in (szOperations)\n| extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)\n| extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)\n| where isnotempty(UserAgent)\n| summarize Count = count() by UserId, Operation, Site_Url, ClientIp\n| summarize AvgCount = avg(Count) by UserId, Operation, Site_Url, ClientIp;\n// Get recent user activity\nlet recentUserActivity = EnrichedMicrosoft365AuditLogs\n| where TimeGenerated > ago(endtime)\n| where RecordType == szSharePointFileOperation\n| where Operation in (szOperations)\n| extend UserAgent = tostring(parse_json(tostring(AdditionalProperties)).UserAgent)\n| extend Site_Url = tostring(parse_json(tostring(AdditionalProperties)).SiteUrl)\n| where isnotempty(UserAgent)\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIp, ObjectId, Workload, UserAgent;\n// Join the baseline and recent activity, and calculate the deviation\nlet UserBehaviorAnalysis = userBaseline \n| join kind=inner (recentUserActivity) on UserId, Operation, Site_Url, ClientIp\n| extend Deviation = abs(RecentCount - AvgCount) / AvgCount;\n// Filter for significant deviations\nUserBehaviorAnalysis\n| where Deviation > threshold\n| project StartTimeUtc, EndTimeUtc, UserId, UserType, Operation, ClientIp, Site_Url, ObjectId, Workload, UserAgent, Deviation, Count=RecentCount\n| order by Count desc, ClientIp asc, Operation asc, UserId asc\n| extend AccountName = tostring(split(UserId, \"@\")[0]), AccountUPNSuffix = tostring(split(UserId, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1030"
        ],
        "templateVersion": "2.0.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}