Dev-0530 File Extension Rename
| Id | d82eb796-d1eb-43c8-a813-325ce3417cef |
| Rulename | Dev-0530 File Extension Rename |
| Description | Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note. |
| Severity | High |
| Tactics | Impact |
| Techniques | T1486 |
| Required data connectors | MicrosoftThreatProtection |
| Kind | Scheduled |
| Query frequency | 1d |
| Query period | 1d |
| Trigger threshold | 0 |
| Trigger operator | gt |
| Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml |
| Version | 1.1.1 |
| Arm template | d82eb796-d1eb-43c8-a813-325ce3417cef.json |
union isfuzzy=true
(DeviceFileEvents
| where ActionType == "FileCreated"
| where FileName endswith ".h0lyenc" or FolderPath == "C:\\FOR_DECRYPT.html"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
by
AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,
DeviceName,
Type,
InitiatingProcessId,
FileName,
FolderPath,
EventType = ActionType,
Commandline = InitiatingProcessCommandLine,
InitiatingProcessFileName,
InitiatingProcessSHA256,
FileHashCustomEntity = SHA256,
AlgorithmCustomEntity = "SHA256"
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
),
(imFileEvent
| where EventType == "FileCreated"
| where TargetFilePath endswith ".h0lyenc" or TargetFilePath == "C:\\FOR_DECRYPT.html"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
by
ActorUsername,
DvcHostname,
DvcDomain,
DvcId,
Type,
EventType,
FileHashCustomEntity = TargetFileSHA256,
Hash,
TargetFilePath,
Commandline = ActingProcessCommandLine,
AlgorithmCustomEntity = "SHA256"
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountDomain = tostring(split(ActorUsername, @'\')[0])
| extend HostName = DvcHostname, HostNameDomain = DvcDomain
| extend DeviceName = strcat(DvcHostname, ".", DvcDomain )
)
id: d82eb796-d1eb-43c8-a813-325ce3417cef
tactics:
- Impact
queryPeriod: 1d
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml
metadata:
categories:
domains:
- Security - Others
source:
kind: Community
support:
tier: Community
author:
name: Microsoft Security Research
triggerThreshold: 0
name: Dev-0530 File Extension Rename
query: |
union isfuzzy=true
(DeviceFileEvents
| where ActionType == "FileCreated"
| where FileName endswith ".h0lyenc" or FolderPath == "C:\\FOR_DECRYPT.html"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
by
AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,
DeviceName,
Type,
InitiatingProcessId,
FileName,
FolderPath,
EventType = ActionType,
Commandline = InitiatingProcessCommandLine,
InitiatingProcessFileName,
InitiatingProcessSHA256,
FileHashCustomEntity = SHA256,
AlgorithmCustomEntity = "SHA256"
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
),
(imFileEvent
| where EventType == "FileCreated"
| where TargetFilePath endswith ".h0lyenc" or TargetFilePath == "C:\\FOR_DECRYPT.html"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
by
ActorUsername,
DvcHostname,
DvcDomain,
DvcId,
Type,
EventType,
FileHashCustomEntity = TargetFileSHA256,
Hash,
TargetFilePath,
Commandline = ActingProcessCommandLine,
AlgorithmCustomEntity = "SHA256"
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountDomain = tostring(split(ActorUsername, @'\')[0])
| extend HostName = DvcHostname, HostNameDomain = DvcDomain
| extend DeviceName = strcat(DvcHostname, ".", DvcDomain )
)
severity: High
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1486
tags:
- Dev-0530
- SchemaVersion: 0.1.0
Schema: ASIMFileEvent
queryFrequency: 1d
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
dataTypes:
- DeviceFileEvents
description: |
'Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note.'
version: 1.1.1
entityMappings:
- fieldMappings:
- columnName: ActorUserName
identifier: FullName
- columnName: AccountName
identifier: Name
- columnName: AccountDomain
identifier: NTDomain
entityType: Account
- fieldMappings:
- columnName: DeviceName
identifier: FullName
- columnName: HostName
identifier: HostName
- columnName: HostNameDomain
identifier: DnsDomain
entityType: Host
- fieldMappings:
- columnName: AlgorithmCustomEntity
identifier: Algorithm
- columnName: FileHashCustomEntity
identifier: Value
entityType: FileHash
{
"$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/d82eb796-d1eb-43c8-a813-325ce3417cef')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d82eb796-d1eb-43c8-a813-325ce3417cef')]",
"properties": {
"alertRuleTemplateName": "d82eb796-d1eb-43c8-a813-325ce3417cef",
"customDetails": null,
"description": "'Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note.'\n",
"displayName": "Dev-0530 File Extension Rename",
"enabled": true,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "ActorUserName",
"identifier": "FullName"
},
{
"columnName": "AccountName",
"identifier": "Name"
},
{
"columnName": "AccountDomain",
"identifier": "NTDomain"
}
]
},
{
"entityType": "Host",
"fieldMappings": [
{
"columnName": "DeviceName",
"identifier": "FullName"
},
{
"columnName": "HostName",
"identifier": "HostName"
},
{
"columnName": "HostNameDomain",
"identifier": "DnsDomain"
}
]
},
{
"entityType": "FileHash",
"fieldMappings": [
{
"columnName": "AlgorithmCustomEntity",
"identifier": "Algorithm"
},
{
"columnName": "FileHashCustomEntity",
"identifier": "Value"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml",
"query": "union isfuzzy=true\n (DeviceFileEvents\n | where ActionType == \"FileCreated\"\n | where FileName endswith \".h0lyenc\" or FolderPath == \"C:\\\\FOR_DECRYPT.html\"\n | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)\n by\n AccountName = InitiatingProcessAccountName, AccountDomain = InitiatingProcessAccountDomain,\n DeviceName,\n Type,\n InitiatingProcessId,\n FileName,\n FolderPath,\n EventType = ActionType,\n Commandline = InitiatingProcessCommandLine,\n InitiatingProcessFileName,\n InitiatingProcessSHA256,\n FileHashCustomEntity = SHA256,\n AlgorithmCustomEntity = \"SHA256\"\n | extend HostName = tostring(split(DeviceName, \".\")[0]), DomainIndex = toint(indexof(DeviceName, '.'))\n | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)\n ),\n (imFileEvent\n | where EventType == \"FileCreated\"\n | where TargetFilePath endswith \".h0lyenc\" or TargetFilePath == \"C:\\\\FOR_DECRYPT.html\"\n | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)\n by\n ActorUsername,\n DvcHostname,\n DvcDomain,\n DvcId,\n Type,\n EventType,\n FileHashCustomEntity = TargetFileSHA256,\n Hash,\n TargetFilePath,\n Commandline = ActingProcessCommandLine,\n AlgorithmCustomEntity = \"SHA256\"\n | extend AccountName = tostring(split(ActorUsername, @'\\')[1]), AccountDomain = tostring(split(ActorUsername, @'\\')[0])\n | extend HostName = DvcHostname, HostNameDomain = DvcDomain\n | extend DeviceName = strcat(DvcHostname, \".\", DvcDomain )\n )\n",
"queryFrequency": "P1D",
"queryPeriod": "P1D",
"severity": "High",
"subTechniques": [],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Impact"
],
"tags": [
"Dev-0530",
{
"Schema": "ASIMFileEvent",
"SchemaVersion": "0.1.0"
}
],
"techniques": [
"T1486"
],
"templateVersion": "1.1.1",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}