Azure-Sentinel/Detections/SecurityEvent/MidnightBlizzard_SuspiciousRundll32Exec.yaml

id: d82e1987-4356-4a7b-bc5e-064f29b143c0
name: Midnight Blizzard - suspicious rundll32.exe execution of vbscript
description: |
  'This query idenifies when rundll32.exe executes a specific set of inline VBScript commands
   References: https://www.microsoft.com/security/blog/2021/03/04/goldmax-goldfinder-sibot-analyzing-nobelium-malware/'
severity: Medium
requiredDataConnectors:
  - connectorId: SecurityEvents
    dataTypes:
      - SecurityEvent
  - connectorId: WindowsSecurityEvents
    dataTypes:
      - SecurityEvent
  - connectorId: WindowsSecurityEvents
    dataTypes: 
      - SecurityEvents
  - connectorId: WindowsForwardedEvents
    dataTypes: 
      - WindowsEvent 
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
relevantTechniques:
  - T1547
tags:
  - Midnight Blizzard
query: |
  (union isfuzzy=true 
  (SecurityEvent
  | where EventID == 4688
  | where Process =~ 'rundll32.exe' 
  | where CommandLine has_all ('Execute','RegRead','window.close')
  | project TimeGenerated, Computer, SubjectAccount = Account, SubjectUserName, SubjectDomainName, SubjectUserSid, Process, ProcessId, NewProcessName, CommandLine, ParentProcessName, _ResourceId
  ),
  (WindowsEvent
  | where EventID == 4688 and EventData has 'rundll32.exe' and EventData has_any ('Execute','RegRead','window.close')
  | extend NewProcessName = tostring(EventData.NewProcessName)
  | extend Process=tostring(split(NewProcessName, '\\')[-1])
  | where Process =~ 'rundll32.exe' 
  | extend CommandLine = tostring(EventData.CommandLine)
  | where CommandLine has_all ('Execute','RegRead','window.close')
  | extend SubjectAccount =  strcat(EventData.SubjectDomainName,"\\", EventData.SubjectUserName)
  | extend ParentProcessName = tostring(EventData.ParentProcessName)  
  | project TimeGenerated, Computer, SubjectAccount, SubjectUserName = EventData.SubjectUserName, SubjectDomainName = EventData.SubjectDomainName, SubjectUserSid = EventData.SubjectUserSid, Process, NewProcessName, CommandLine, ParentProcessName, _ResourceId
  )
  )
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | project-away DomainIndex
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: SubjectAccount
      - identifier: Name
        columnName: SubjectUserName
      - identifier: NTDomain
        columnName: SubjectDomainName
  - entityType: Account
    fieldMappings:
      - identifier: Sid
        columnName: SubjectUserSid
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Computer
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: HostNameDomain
version: 1.1.5
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Microsoft Security Research
    support:
        tier: Community
    categories:
        domains: [ "Security - Threat Intelligence" ]