Analyzing Windows Shellbag Artifacts
Overview
Shellbags are Windows registry artifacts that track how users interact with folders through Windows Explorer, storing view settings such as icon size, window position, sort order, and view mode. From a forensic perspective, Shellbags provide definitive evidence of folder access -- even folders that no longer exist on the system. When a user browses to a folder via Windows Explorer, the Open/Save dialog, or the Control Panel, a Shellbag entry is created or updated in the user's registry hive. These entries persist after folder deletion, drive disconnection, and even across user profile resets, making them invaluable for proving that a user navigated to specific directories on local drives, USB devices, network shares, or zip archives.
Registry Locations
Windows 7/8/10/11
| Hive | Key Path | Stores |
|---|---|---|
| NTUSER.DAT | Software\Microsoft\Windows\Shell\BagMRU | Folder hierarchy tree |
| NTUSER.DAT | Software\Microsoft\Windows\Shell\Bags | View settings per folder |
| UsrClass.dat | Local Settings\Software\Microsoft\Windows\Shell\BagMRU | Desktop/Explorer shell |
| UsrClass.dat | Local Settings\Software\Microsoft\Windows\Shell\Bags | Additional view settings |
BagMRU Structure
The BagMRU key contains a hierarchical tree of numbered subkeys representing the directory structure. Each subkey value contains a Shell Item (SHITEMID) binary blob encoding the folder identity:
- Root (BagMRU): Desktop namespace root
- BagMRU\0: Typically "My Computer"
- BagMRU\0\0: First drive (e.g., C:)
- BagMRU\0\0\0: First subfolder on C:
Each Shell Item contains:
- Item type (folder, drive, network, zip, control panel)
- Short name (8.3 format)
- Long name (Unicode)
- Creation/modification timestamps
- MFT entry/sequence for NTFS folders
Analysis with EZ Tools
SBECmd (Command Line)
# Parse shellbags from a directory of registry hives
SBECmd.exe -d "C:\Evidence\Registry" --csv C:\Output --csvf shellbags.csv
# Parse from a live system (requires admin)
SBECmd.exe --live --csv C:\Output --csvf live_shellbags.csv
# Key output columns:
# AbsolutePath - Full reconstructed path
# CreatedOn - When the folder was first browsed
# ModifiedOn - When view settings were last changed
# AccessedOn - Last access timestamp
# ShellType - Type of shell item (Directory, Drive, Network, etc.)
# Value - Raw shell item data
ShellBags Explorer (GUI)
# Launch GUI tool for interactive analysis
ShellBagsExplorer.exe
# Load registry hives: File > Load Hive
# Navigate the tree structure to see folder hierarchy
# Right-click entries for detailed shell item properties
Forensic Investigation Scenarios
Proving USB Device Browsing
Shellbag Path: My Computer\E:\Confidential\Project_Files
ShellType: Directory (on removable volume)
CreatedOn: 2025-03-15 09:30:00 UTC
This proves the user navigated to E:\Confidential\Project_Files
via Windows Explorer, even if the USB drive is no longer connected.
The volume letter E: and directory timestamps can be correlated
with USBSTOR and MountPoints2 registry entries.
Detecting Network Share Access
Shellbag Path: \\FileServer01\Finance\Q4_Reports
ShellType: Network Location
AccessedOn: 2025-02-20 14:15:00 UTC
This proves the user browsed to a network share, even if
the share has been decommissioned or access revoked.
Identifying Deleted Folder Knowledge
Shellbag Path: C:\Users\suspect\Documents\Exfiltration_Staging
ShellType: Directory
CreatedOn: 2025-01-10 08:00:00 UTC
Even though C:\Users\suspect\Documents\Exfiltration_Staging
no longer exists, the Shellbag entry proves the user
created and navigated to this folder.
Limitations
- Shellbags only record folder-level interactions, not individual file access
- Only created through Windows Explorer shell and Open/Save dialogs
- Command-line access (cmd, PowerShell) does not generate Shellbag entries
- Programmatic file access via APIs does not generate Shellbag entries
- Timestamps may reflect view setting changes, not necessarily folder access
- Windows may batch-update Shellbag entries during Explorer shutdown
Verification Criteria
Confirm successful execution by validating:
- [ ] All prerequisite tools and access requirements are satisfied
- [ ] Each workflow step completed without errors
- [ ] Output matches expected format and contains expected data
- [ ] No security warnings or misconfigurations detected
- [ ] Results are documented and evidence is preserved for audit
Compliance Framework Mapping
This skill supports compliance evidence collection across multiple frameworks:
- SOC 2: CC7.3 (Incident Identification), CC7.4 (Incident Response)
- ISO 27001: A.16.1 (Security Incident Management), A.12.4 (Logging)
- NIST 800-53: AU-6 (Audit Review), IR-4 (Incident Handling), AU-9 (Audit Protection)
- NIST CSF: RS.AN (Analysis), RS.RP (Response Planning)
Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.
Deploying This Skill with Claw GRC
Agent Execution
Register this skill with your Claw GRC agent for automated execution:
# Install via CLI
npx claw-grc skills add analyzing-windows-shellbag-artifacts
# Or load dynamically via MCP
grc.load_skill("analyzing-windows-shellbag-artifacts")
Audit Trail Integration
When executed through Claw GRC, every step of this skill generates tamper-evident audit records:
- SHA-256 chain hashing ensures no step can be modified after execution
- Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
- Trust score impact — successful execution increases your agent's trust score
Continuous Compliance
Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.
References
- Shellbags Forensic Analysis 2025: https://www.cybertriage.com/blog/shellbags-forensic-analysis-2025/
- SANS Shellbag Forensics: https://www.sans.org/blog/computer-forensic-artifacts-windows-7-shellbags
- Magnet Forensics Shellbag Analysis: https://www.magnetforensics.com/blog/forensic-analysis-of-windows-shellbags/
- ShellBags Explorer: https://ericzimmerman.github.io/