Malware in the recycle bin

Back


Id	75bf9902-0789-47c1-a5d8-f57046aa72df
Rulename	Malware in the recycle bin
Description	The query detects Windows binaries, that can be used for executing malware, that have been hidden in the recycle bin. The list of these binaries are sourced from https://lolbas-project.github.io/ References: https://azure.microsoft.com/blog/how-azure-security-center-helps-reveal-a-cyberattack/.
Severity	Medium
Tactics	DefenseEvasion
Required data connectors	SecurityEvents WindowsForwardedEvents WindowsSecurityEvents
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint Threat Protection Essentials/Analytic Rules/malware_in_recyclebin.yaml
Version	1.1.2
Arm template	75bf9902-0789-47c1-a5d8-f57046aa72df.json

KQL

let procList = externaldata(Process:string) [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Microsoft_Lolbas_Execution_Binaries.csv"] with (format="csv", ignoreFirstRecord=True);
let recycle_bin_paths = dynamic([@":\RECYCLER", @":\$RECYCLE.BIN"]);
let ProcessCreationEvents=() {
let processEvents=(union isfuzzy=true
(SecurityEvent
| where EventID==4688
| where isnotempty(CommandLine)
| project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,
FileName = Process, CommandLine,  ParentProcessName
),
(WindowsEvent
| where EventID==4688 and EventData has_any (procList) and EventData has_any (recycle_bin_paths)
| extend CommandLine = tostring(EventData.CommandLine)
| where isnotempty(CommandLine)
| extend SubjectUserName = tostring(EventData.SubjectUserName)
| extend SubjectDomainName = tostring(EventData.SubjectDomainName) 
| extend NewProcessName = tostring(EventData.NewProcessName)  
| extend ParentProcessName = tostring(EventData.ParentProcessName)
| extend Process=tostring(split(NewProcessName, '\\')[-1])
| project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,
FileName = Process, CommandLine,  ParentProcessName
));
processEvents};
ProcessCreationEvents 
| where FileName in~ (procList)
| where CommandLine has_any (recycle_bin_paths)
| project StartTimeUtc = TimeGenerated, Computer, Account, NewProcessName, FileName, CommandLine, ParentProcessName
| extend timestamp = StartTimeUtc, AccountCustomEntity = Account, HostCustomEntity = Computer

YAML

version: 1.1.2
status: Available
queryFrequency: 1d
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvents
- connectorId: WindowsForwardedEvents
  dataTypes:
  - WindowsEvent
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: HostCustomEntity
    identifier: FullName
  entityType: Host
kind: Scheduled
queryPeriod: 1d
severity: Medium
query: |
  let procList = externaldata(Process:string) [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Microsoft_Lolbas_Execution_Binaries.csv"] with (format="csv", ignoreFirstRecord=True);
  let recycle_bin_paths = dynamic([@":\RECYCLER", @":\$RECYCLE.BIN"]);
  let ProcessCreationEvents=() {
  let processEvents=(union isfuzzy=true
  (SecurityEvent
  | where EventID==4688
  | where isnotempty(CommandLine)
  | project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,
  FileName = Process, CommandLine,  ParentProcessName
  ),
  (WindowsEvent
  | where EventID==4688 and EventData has_any (procList) and EventData has_any (recycle_bin_paths)
  | extend CommandLine = tostring(EventData.CommandLine)
  | where isnotempty(CommandLine)
  | extend SubjectUserName = tostring(EventData.SubjectUserName)
  | extend SubjectDomainName = tostring(EventData.SubjectDomainName) 
  | extend NewProcessName = tostring(EventData.NewProcessName)  
  | extend ParentProcessName = tostring(EventData.ParentProcessName)
  | extend Process=tostring(split(NewProcessName, '\\')[-1])
  | project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,
  FileName = Process, CommandLine,  ParentProcessName
  ));
  processEvents};
  ProcessCreationEvents 
  | where FileName in~ (procList)
  | where CommandLine has_any (recycle_bin_paths)
  | project StartTimeUtc = TimeGenerated, Computer, Account, NewProcessName, FileName, CommandLine, ParentProcessName
  | extend timestamp = StartTimeUtc, AccountCustomEntity = Account, HostCustomEntity = Computer  
triggerOperator: gt
id: 75bf9902-0789-47c1-a5d8-f57046aa72df
description: |
  'The query detects Windows binaries, that can be used for executing malware, that have been hidden in the recycle bin. 
   The list of these binaries are sourced from https://lolbas-project.github.io/
   References: https://azure.microsoft.com/blog/how-azure-security-center-helps-reveal-a-cyberattack/.'  
triggerThreshold: 0
name: Malware in the recycle bin
tactics:
- DefenseEvasion
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint Threat Protection Essentials/Analytic Rules/malware_in_recyclebin.yaml

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/75bf9902-0789-47c1-a5d8-f57046aa72df')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/75bf9902-0789-47c1-a5d8-f57046aa72df')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "Malware in the recycle bin",
        "description": "'The query detects Windows binaries, that can be used for executing malware, that have been hidden in the recycle bin. \n The list of these binaries are sourced from https://lolbas-project.github.io/\n References: https://azure.microsoft.com/blog/how-azure-security-center-helps-reveal-a-cyberattack/.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let procList = externaldata(Process:string) [@\"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Microsoft_Lolbas_Execution_Binaries.csv\"] with (format=\"csv\", ignoreFirstRecord=True);\nlet recycle_bin_paths = dynamic([@\":\\RECYCLER\", @\":\\$RECYCLE.BIN\"]);\nlet ProcessCreationEvents=() {\nlet processEvents=(union isfuzzy=true\n(SecurityEvent\n| where EventID==4688\n| where isnotempty(CommandLine)\n| project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,\nFileName = Process, CommandLine,  ParentProcessName\n),\n(WindowsEvent\n| where EventID==4688 and EventData has_any (procList) and EventData has_any (recycle_bin_paths)\n| extend CommandLine = tostring(EventData.CommandLine)\n| where isnotempty(CommandLine)\n| extend SubjectUserName = tostring(EventData.SubjectUserName)\n| extend SubjectDomainName = tostring(EventData.SubjectDomainName) \n| extend NewProcessName = tostring(EventData.NewProcessName)  \n| extend ParentProcessName = tostring(EventData.ParentProcessName)\n| extend Process=tostring(split(NewProcessName, '\\\\')[-1])\n| project TimeGenerated, Computer, Account = SubjectUserName, AccountDomain = SubjectDomainName, NewProcessName,\nFileName = Process, CommandLine,  ParentProcessName\n));\nprocessEvents};\nProcessCreationEvents \n| where FileName in~ (procList)\n| where CommandLine has_any (recycle_bin_paths)\n| project StartTimeUtc = TimeGenerated, Computer, Account, NewProcessName, FileName, CommandLine, ParentProcessName\n| extend timestamp = StartTimeUtc, AccountCustomEntity = Account, HostCustomEntity = Computer\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "alertRuleTemplateName": "75bf9902-0789-47c1-a5d8-f57046aa72df",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "HostCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint Threat Protection Essentials/Analytic Rules/malware_in_recyclebin.yaml",
        "status": "Available",
        "templateVersion": "1.1.2"
      }
    }
  ]
}