File System Logical Offsets
|File System Logical Offsets|
|Data Sources||API monitoring|
|Defense Bypassed||File monitoring, File system access controls|
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 bypasses Windows file access controls as well as file system monitoring tools.1
Utilities, such as NinjaCopy, exist to perform these actions in PowerShell.2
Identify potentially malicious software that may be used to access logical drives in this manner, and audit and/or block it by using whitelisting3 tools, like AppLocker,45 or Software Restriction Policies6 where appropriate.7
Monitor handle opens on drive volumes that are made by processes to determine when they may directly access logical drives.2
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.
- 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.
- Beechey, J. (2010, December). Application Whitelisting: Panacea or Propaganda?. Retrieved November 18, 2014.
- Tomonaga, S. (2016, January 26). Windows Commands Abused by Attackers. Retrieved February 2, 2016.
- NSA Information Assurance Directorate. (2014, August). Application Whitelisting Using Microsoft AppLocker. Retrieved March 31, 2016.
- Corio, C., & Sayana, D. P. (2008, June). Application Lockdown with Software Restriction Policies. Retrieved November 18, 2014.
- Microsoft. (2012, June 27). Using Software Restriction Policies and AppLocker Policies. Retrieved April 7, 2016.