// 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])
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft 365/Analytic Rules/SharePoint_Downloads_byNewIP.yaml
queryPeriod: 14d
version: 2.0.4
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
queryFrequency: 1d
triggerOperator: gt
kind: Scheduled
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])
id: 4b11568b-3f5f-4ba1-80c8-7f1dc8390eb7
tactics:
- Exfiltration
status: Available
requiredDataConnectors:
- connectorId: Office365
dataTypes:
- OfficeActivity
triggerThreshold: 0
name: SharePointFileOperation via previously unseen IPs
severity: Medium
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.'
