Power Automate - Unusual bulk deletion of flow resources
Id | 56cb646e-56a0-4f0e-8866-9bc1dd15da78 |
Rulename | Power Automate - Unusual bulk deletion of flow resources |
Description | Identifies bulk deletion of Power Automate flows that exceed a predefined threshold defined in the query and deviate from activity patterns observed in the last 14 days. |
Severity | Medium |
Tactics | Impact DefenseEvasion |
Techniques | T1485 T0828 T1562 |
Required data connectors | PowerAutomate |
Kind | Scheduled |
Query frequency | 1h |
Query period | 14d |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Business Applications/Analytic Rules/Power Automate - Unusual bulk deletion of flow resources.yaml |
Version | 3.2.0 |
Arm template | 56cb646e-56a0-4f0e-8866-9bc1dd15da78.json |
// minThreshold: Minimum number of apps to be deleted to be considered an anomaly;
// This is to prevent one-off isolated delete flow to be considered outlier.
// The Min Threshold can be reduced or increased according to the traffic in the organization.
let minThreshold=10;
let interval = 1h;
let startTime = ago(14d);
let endTime = now();
let query_frequency = 1h;
let flow_deletion_events = PowerAutomateActivity
| where TimeGenerated >= startTime
| where EventOriginalType =~ "DeleteFlow"
| extend IngestionTimeGenerated = TimeGenerated;
flow_deletion_events
| make-series DeletedFlowCount=count() on IngestionTimeGenerated from startTime to endTime step interval by ActorName, UserUpn, ActorUserId
| extend(Anomalies, AnomalyScore, ExpectedUsage) = series_decompose_anomalies(DeletedFlowCount)
| mv-expand
DeletedFlowCount to typeof(double),
IngestionTimeGenerated to typeof(datetime),
Anomalies to typeof(double),
AnomalyScore to typeof(double),
ExpectedUsage to typeof(long)
| where IngestionTimeGenerated >= ago(query_frequency)
| where Anomalies != 0 and DeletedFlowCount >= minThreshold
| lookup (flow_deletion_events
| where IngestionTimeGenerated >= ago(query_frequency))
on ActorName, UserUpn, ActorUserId
| extend
AccountName = tostring(split(ActorName, "@")[0]),
UPNSuffix = tostring(split(ActorName, "@")[1]),
PowerAutomateAppId = 27592
| project
TimeGenerated,
ActorName,
DeletedFlowCount,
ExpectedUsage,
Anomalies,
AnomalyScore,
AccountName,
UPNSuffix,
PowerAutomateAppId,
UserUpn,
ActorUserId
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: AccountName
- identifier: UPNSuffix
columnName: UPNSuffix
- entityType: CloudApplication
fieldMappings:
- identifier: AppId
columnName: PowerAutomateAppId
queryFrequency: 1h
name: Power Automate - Unusual bulk deletion of flow resources
alertDetailsOverride:
alertDisplayNameFormat: Power Automate - unusual bulk deletion of {{DeletedFlowCount}} flows
alertDescriptionFormat: User {{ActorName}} deleted {{DeletedFlowCount}} flows in the last hour, surpassing the bulk delete threshold. This is anomalous compared to the past 14 days.
kind: Scheduled
tactics:
- Impact
- DefenseEvasion
triggerThreshold: 0
query: |
// minThreshold: Minimum number of apps to be deleted to be considered an anomaly;
// This is to prevent one-off isolated delete flow to be considered outlier.
// The Min Threshold can be reduced or increased according to the traffic in the organization.
let minThreshold=10;
let interval = 1h;
let startTime = ago(14d);
let endTime = now();
let query_frequency = 1h;
let flow_deletion_events = PowerAutomateActivity
| where TimeGenerated >= startTime
| where EventOriginalType =~ "DeleteFlow"
| extend IngestionTimeGenerated = TimeGenerated;
flow_deletion_events
| make-series DeletedFlowCount=count() on IngestionTimeGenerated from startTime to endTime step interval by ActorName, UserUpn, ActorUserId
| extend(Anomalies, AnomalyScore, ExpectedUsage) = series_decompose_anomalies(DeletedFlowCount)
| mv-expand
DeletedFlowCount to typeof(double),
IngestionTimeGenerated to typeof(datetime),
Anomalies to typeof(double),
AnomalyScore to typeof(double),
ExpectedUsage to typeof(long)
| where IngestionTimeGenerated >= ago(query_frequency)
| where Anomalies != 0 and DeletedFlowCount >= minThreshold
| lookup (flow_deletion_events
| where IngestionTimeGenerated >= ago(query_frequency))
on ActorName, UserUpn, ActorUserId
| extend
AccountName = tostring(split(ActorName, "@")[0]),
UPNSuffix = tostring(split(ActorName, "@")[1]),
PowerAutomateAppId = 27592
| project
TimeGenerated,
ActorName,
DeletedFlowCount,
ExpectedUsage,
Anomalies,
AnomalyScore,
AccountName,
UPNSuffix,
PowerAutomateAppId,
UserUpn,
ActorUserId
relevantTechniques:
- T1485
- T0828
- T1562
triggerOperator: gt
customDetails:
DeletedFlowCount: DeletedFlowCount
queryPeriod: 14d
eventGroupingSettings:
aggregationKind: SingleAlert
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Business Applications/Analytic Rules/Power Automate - Unusual bulk deletion of flow resources.yaml
severity: Medium
status: Available
id: 56cb646e-56a0-4f0e-8866-9bc1dd15da78
requiredDataConnectors:
- connectorId: PowerAutomate
dataTypes:
- PowerAutomateActivity
version: 3.2.0
description: Identifies bulk deletion of Power Automate flows that exceed a predefined threshold defined in the query and deviate from activity patterns observed in the last 14 days.
{
"$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/56cb646e-56a0-4f0e-8866-9bc1dd15da78')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/56cb646e-56a0-4f0e-8866-9bc1dd15da78')]",
"properties": {
"alertDetailsOverride": {
"alertDescriptionFormat": "User {{ActorName}} deleted {{DeletedFlowCount}} flows in the last hour, surpassing the bulk delete threshold. This is anomalous compared to the past 14 days.",
"alertDisplayNameFormat": "Power Automate - unusual bulk deletion of {{DeletedFlowCount}} flows"
},
"alertRuleTemplateName": "56cb646e-56a0-4f0e-8866-9bc1dd15da78",
"customDetails": {
"DeletedFlowCount": "DeletedFlowCount"
},
"description": "Identifies bulk deletion of Power Automate flows that exceed a predefined threshold defined in the query and deviate from activity patterns observed in the last 14 days.",
"displayName": "Power Automate - Unusual bulk deletion of flow resources",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "AccountName",
"identifier": "Name"
},
{
"columnName": "UPNSuffix",
"identifier": "UPNSuffix"
}
]
},
{
"entityType": "CloudApplication",
"fieldMappings": [
{
"columnName": "PowerAutomateAppId",
"identifier": "AppId"
}
]
}
],
"eventGroupingSettings": {
"aggregationKind": "SingleAlert"
},
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Business Applications/Analytic Rules/Power Automate - Unusual bulk deletion of flow resources.yaml",
"query": "// minThreshold: Minimum number of apps to be deleted to be considered an anomaly;\n// This is to prevent one-off isolated delete flow to be considered outlier.\n// The Min Threshold can be reduced or increased according to the traffic in the organization.\nlet minThreshold=10;\nlet interval = 1h;\nlet startTime = ago(14d);\nlet endTime = now();\nlet query_frequency = 1h;\nlet flow_deletion_events = PowerAutomateActivity\n | where TimeGenerated >= startTime\n | where EventOriginalType =~ \"DeleteFlow\"\n | extend IngestionTimeGenerated = TimeGenerated;\nflow_deletion_events\n| make-series DeletedFlowCount=count() on IngestionTimeGenerated from startTime to endTime step interval by ActorName, UserUpn, ActorUserId\n| extend(Anomalies, AnomalyScore, ExpectedUsage) = series_decompose_anomalies(DeletedFlowCount)\n| mv-expand\n DeletedFlowCount to typeof(double),\n IngestionTimeGenerated to typeof(datetime),\n Anomalies to typeof(double),\n AnomalyScore to typeof(double),\n ExpectedUsage to typeof(long)\n| where IngestionTimeGenerated >= ago(query_frequency)\n| where Anomalies != 0 and DeletedFlowCount >= minThreshold\n| lookup (flow_deletion_events\n | where IngestionTimeGenerated >= ago(query_frequency))\n on ActorName, UserUpn, ActorUserId\n| extend\n AccountName = tostring(split(ActorName, \"@\")[0]),\n UPNSuffix = tostring(split(ActorName, \"@\")[1]),\n PowerAutomateAppId = 27592\n| project\n TimeGenerated,\n ActorName,\n DeletedFlowCount,\n ExpectedUsage,\n Anomalies,\n AnomalyScore,\n AccountName,\n UPNSuffix,\n PowerAutomateAppId,\n UserUpn,\n ActorUserId\n",
"queryFrequency": "PT1H",
"queryPeriod": "P14D",
"severity": "Medium",
"status": "Available",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"DefenseEvasion",
"Impact"
],
"techniques": [
"T1485",
"T1562"
],
"templateVersion": "3.2.0",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}