SharePointFileOperation via previously unseen IPs

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Id	4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7
Rulename	SharePointFileOperation 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	Office365
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/Microsoft 365/Analytic Rules/SharePoint_Downloads_byNewIP.yaml
Version	2.0.4
Arm template	4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7.json

KQL

// Define a threshold for significant deviations
let threshold = 25;
// Define the name for the SharePoint File Operation record type
let szSharePointFileOperation = "SharePointFileOperation";
// Define an array of SharePoint operations of interest
let szOperations = dynamic(["FileDownloaded", "FileUploaded"]);
// Define the start and end time for the analysis period
let starttime = 14d;
let endtime = 1d;
// Define a baseline of normal user behavior
let userBaseline = OfficeActivity
| where TimeGenerated between(ago(starttime)..ago(endtime))
| where RecordType =~ szSharePointFileOperation
| where Operation in~ (szOperations)
| 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 = OfficeActivity
| where TimeGenerated > ago(endtime)
| where RecordType =~ szSharePointFileOperation
| where Operation in~ (szOperations)
| where isnotempty(UserAgent)
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIP, OfficeObjectId, OfficeWorkload, 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, OfficeObjectId, OfficeWorkload, 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

status: Available
triggerThreshold: 0
version: 2.0.4
queryFrequency: 1d
tactics:
- Exfiltration
name: SharePointFileOperation via previously unseen IPs
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/SharePoint_Downloads_byNewIP.yaml
queryPeriod: 14d
id: 4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7
query: |
  // Define a threshold for significant deviations
  let threshold = 25;
  // Define the name for the SharePoint File Operation record type
  let szSharePointFileOperation = "SharePointFileOperation";
  // Define an array of SharePoint operations of interest
  let szOperations = dynamic(["FileDownloaded", "FileUploaded"]);
  // Define the start and end time for the analysis period
  let starttime = 14d;
  let endtime = 1d;
  // Define a baseline of normal user behavior
  let userBaseline = OfficeActivity
  | where TimeGenerated between(ago(starttime)..ago(endtime))
  | where RecordType =~ szSharePointFileOperation
  | where Operation in~ (szOperations)
  | 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 = OfficeActivity
  | where TimeGenerated > ago(endtime)
  | where RecordType =~ szSharePointFileOperation
  | where Operation in~ (szOperations)
  | where isnotempty(UserAgent)
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIP, OfficeObjectId, OfficeWorkload, 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, OfficeObjectId, OfficeWorkload, 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
severity: Medium
triggerOperator: gt
requiredDataConnectors:
- dataTypes:
  - OfficeActivity
  connectorId: Office365
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: UserId
  - identifier: Name
    columnName: AccountName
  - identifier: UPNSuffix
    columnName: AccountUPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: ClientIP
  entityType: IP
- fieldMappings:
  - identifier: Url
    columnName: Site_Url
  entityType: URL
relevantTechniques:
- T1030
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.'

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/4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7')]",
      "properties": {
        "alertRuleTemplateName": "4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7",
        "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": "SharePointFileOperation 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/Microsoft 365/Analytic Rules/SharePoint_Downloads_byNewIP.yaml",
        "query": "// Define a threshold for significant deviations\nlet threshold = 25;\n// Define the name for the SharePoint File Operation record type\nlet szSharePointFileOperation = \"SharePointFileOperation\";\n// Define an array of SharePoint operations of interest\nlet szOperations = dynamic([\"FileDownloaded\", \"FileUploaded\"]);\n// Define the start and end time for the analysis period\nlet starttime = 14d;\nlet endtime = 1d;\n// Define a baseline of normal user behavior\nlet userBaseline = OfficeActivity\n| where TimeGenerated between(ago(starttime)..ago(endtime))\n| where RecordType =~ szSharePointFileOperation\n| where Operation in~ (szOperations)\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 = OfficeActivity\n| where TimeGenerated > ago(endtime)\n| where RecordType =~ szSharePointFileOperation\n| where Operation in~ (szOperations)\n| where isnotempty(UserAgent)\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), RecentCount = count() by UserId, UserType, Operation, Site_Url, ClientIP, OfficeObjectId, OfficeWorkload, UserAgent;\n// Join the baseline and recent activity, and calculate the deviation\nlet UserBehaviorAnalysis = userBaseline | 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, OfficeObjectId, OfficeWorkload, 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": "2.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}