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 )
)
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
triggerThreshold: 0
severity: High
queryFrequency: 1d
queryPeriod: 1d
relevantTechniques:
- T1486
triggerOperator: gt
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.'
id: d82eb796-d1eb-43c8-a813-325ce3417cef
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
dataTypes:
- DeviceFileEvents
version: 1.1.1
name: Dev-0530 File Extension Rename
metadata:
categories:
domains:
- Security - Others
author:
name: Microsoft Security Research
support:
tier: Community
source:
kind: Community
tags:
- Dev-0530
- Schema: ASIMFileEvent
SchemaVersion: 0.1.0
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 )
)
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/MultipleDataSources/Dev-0530_FileExtRename.yaml
kind: Scheduled
{
"$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"
}
]
}