Direct Volume Access
Adversaries may directly access a volume to bypass file access controls and file system monitoring. Windows allows programs to have direct access to logical volumes. Programs with direct access may read and write files directly from the drive by analyzing file system data structures. This technique may bypass Windows file access controls as well as file system monitoring tools. (Citation: Hakobyan 2009) Utilities, such as `NinjaCopy`, exist to perform these actions in PowerShell.(Citation: Github PowerSploit Ninjacopy) Adversaries may also use built-in or third-party utilities (such as `vssadmin`, `wbadmin`, and esentutl) to create shadow copies or backups of data from system volumes.(Citation: LOLBAS Esentutl)
Procedure Examples |
|
| Name | Description |
|---|---|
| esentutl |
esentutl can use the Volume Shadow Copy service to copy locked files such as `ntds.dit`.(Citation: LOLBAS Esentutl)(Citation: Cary Esentutl) |
| Scattered Spider |
Scattered Spider has created volume shadow copies of virtual domain controller disks to extract the `NTDS.dit` file.(Citation: MSTIC Octo Tempest Operations October 2023) |
| Volt Typhoon |
Volt Typhoon has executed the Windows-native `vssadmin` command to create volume shadow copies.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024) |
Mitigations |
|
| Mitigation | Description |
|---|---|
| File System Logical Offsets Mitigation |
Identify potentially malicious software that may be used to access logical drives in this manner, and audit and/or block it by using whitelisting (Citation: Beechey 2010) tools, like AppLocker, (Citation: Windows Commands JPCERT) (Citation: NSA MS AppLocker) or Software Restriction Policies (Citation: Corio 2008) where appropriate. (Citation: TechNet Applocker vs SRP) |
| Behavior Prevention on Endpoint |
Use capabilities to prevent suspicious behavior patterns from occurring on endpoint systems. This could include suspicious process, file, API call, etc. behavior. |
| User Account Management |
Manage the creation, modification, use, and permissions associated to user accounts. |
Detection
Monitor handle opens on drive volumes that are made by processes to determine when they may directly access logical drives. (Citation: Github PowerSploit Ninjacopy) Monitor processes and command-line arguments for actions that could be taken to copy files from the logical drive and evade common file system protections. Since this technique may also be used through PowerShell, additional logging of PowerShell scripts is recommended.
References
- LOLBAS. (n.d.). Esentutl.exe. Retrieved September 3, 2019.
- Hakobyan, A. (2009, January 8). FDump - Dumping File Sectors Directly from Disk using Logical Offsets. Retrieved November 12, 2014.
- Bialek, J. (2015, December 16). Invoke-NinjaCopy.ps1. Retrieved June 2, 2016.
- Cary, M. (2018, December 6). Locked File Access Using ESENTUTL.exe. Retrieved September 5, 2019.
- Microsoft. (2023, October 25). Octo Tempest crosses boundaries to facilitate extortion, encryption, and destruction. Retrieved March 18, 2024.
- CISA et al.. (2024, February 7). PRC State-Sponsored Actors Compromise and Maintain Persistent Access to U.S. Critical Infrastructure. Retrieved May 15, 2024.
Связанные риски
| Риск | Связи | |
|---|---|---|
|
Обход систем защиты
из-за
возможности получения прямого доступа к тому (volume)
в ОС Windows
Повышение привилегий
Целостность
|
|
Каталоги
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