Detectionmediumtest

Access To Windows DPAPI Master Keys By Uncommon Applications

Detects file access requests to the the Windows Data Protection API Master keys by an uncommon application. This can be a sign of credential stealing. Example case would be usage of mimikatz "dpapi::masterkey" function

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Mon Oct 17Updated Mon Jul 2946612ae6-86be-4802-bc07-39b59feb1309windows
Log Source
Windowsfile_access
ProductWindows← raw: windows
Categoryfile_access← raw: file_access

Definition

Requirements: Microsoft-Windows-Kernel-File ETW provider

Detection Logic
Detection Logic2 selectors
detection:
    selection:
        FileName|contains:
            - '\Microsoft\Protect\S-1-5-18\' # For System32
            - '\Microsoft\Protect\S-1-5-21-' # For Users
    filter_system_folders:
        Image|startswith:
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
            - 'C:\Windows\system32\'
            - 'C:\Windows\SysWOW64\'
    condition: selection and not 1 of filter_*
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
46612ae6-86be-4802-bc07-39b59feb1309
Status
test
Level
medium
Type
Detection
Created
Mon Oct 17
Modified
Mon Jul 29
Path
rules/windows/file/file_access/file_access_win_susp_dpapi_master_key_access.yml
Raw Tags
attack.credential-accessattack.t1555.004
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