Base64 encoded Windows process command-lines (Normalized Process Events)
Id | f8b3c49c-4087-499b-920f-0dcfaff0cbca |
Rulename | Base64 encoded Windows process command-lines (Normalized Process Events) |
Description | Identifies instances of a base64 encoded PE file header seen in the process command line parameter. To use this analytics rule, make sure you have deployed the ASIM normalization parsers |
Severity | Medium |
Tactics | Execution DefenseEvasion |
Techniques | T1059 T1027 T1140 |
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/ASimProcess/imProcess_base64_encoded_pefile.yaml |
Version | 1.1.2 |
Arm template | f8b3c49c-4087-499b-920f-0dcfaff0cbca.json |
imProcessCreate
| where CommandLine contains "TVqQAAMAAAAEAAA"
| where isnotempty(Process)
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by Dvc, ActorUsername, Process, CommandLine, ActingProcessName, EventVendor, EventProduct
| extend timestamp = StartTimeUtc, AccountCustomEntity = ActorUsername, HostCustomEntity = Dvc
metadata:
author:
name: Yuval Naor
support:
tier: Community
source:
kind: Community
categories:
domains:
- Security - Threat Protection
severity: Medium
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimProcess/imProcess_base64_encoded_pefile.yaml
description: |
'Identifies instances of a base64 encoded PE file header seen in the process command line parameter.
To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimProcessEvent)'
tags:
- Id: ca67c83e-7fff-4127-a3e3-1af66d6d4cad
version: 1.0.0
- SchemaVersion: 0.1.0
Schema: ASIMProcessEvent
triggerOperator: gt
queryPeriod: 1d
requiredDataConnectors: []
queryFrequency: 1d
triggerThreshold: 0
tactics:
- Execution
- DefenseEvasion
query: |
imProcessCreate
| where CommandLine contains "TVqQAAMAAAAEAAA"
| where isnotempty(Process)
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by Dvc, ActorUsername, Process, CommandLine, ActingProcessName, EventVendor, EventProduct
| extend timestamp = StartTimeUtc, AccountCustomEntity = ActorUsername, HostCustomEntity = Dvc
kind: Scheduled
relevantTechniques:
- T1059
- T1027
- T1140
version: 1.1.2
id: f8b3c49c-4087-499b-920f-0dcfaff0cbca
entityMappings:
- fieldMappings:
- columnName: AccountCustomEntity
identifier: FullName
entityType: Account
- fieldMappings:
- columnName: HostCustomEntity
identifier: FullName
entityType: Host
name: Base64 encoded Windows process command-lines (Normalized Process Events)
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/f8b3c49c-4087-499b-920f-0dcfaff0cbca')]",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f8b3c49c-4087-499b-920f-0dcfaff0cbca')]",
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
"kind": "Scheduled",
"apiVersion": "2022-11-01-preview",
"properties": {
"displayName": "Base64 encoded Windows process command-lines (Normalized Process Events)",
"description": "'Identifies instances of a base64 encoded PE file header seen in the process command line parameter.\nTo use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimProcessEvent)'\n",
"severity": "Medium",
"enabled": true,
"query": "imProcessCreate\n | where CommandLine contains \"TVqQAAMAAAAEAAA\"\n | where isnotempty(Process)\n | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), count() by Dvc, ActorUsername, Process, CommandLine, ActingProcessName, EventVendor, EventProduct\n | extend timestamp = StartTimeUtc, AccountCustomEntity = ActorUsername, HostCustomEntity = Dvc\n",
"queryFrequency": "P1D",
"queryPeriod": "P1D",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0,
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Execution",
"DefenseEvasion"
],
"techniques": [
"T1059",
"T1027",
"T1140"
],
"alertRuleTemplateName": "f8b3c49c-4087-499b-920f-0dcfaff0cbca",
"customDetails": null,
"entityMappings": [
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "AccountCustomEntity",
"identifier": "FullName"
}
]
},
{
"entityType": "Host",
"fieldMappings": [
{
"columnName": "HostCustomEntity",
"identifier": "FullName"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimProcess/imProcess_base64_encoded_pefile.yaml",
"tags": [
{
"Id": "ca67c83e-7fff-4127-a3e3-1af66d6d4cad",
"version": "1.0.0"
},
{
"Schema": "ASIMProcessEvent",
"SchemaVersion": "0.1.0"
}
],
"templateVersion": "1.1.2"
}
}
]
}