| name | analyzing-windows-shellbag-artifacts |
| description | Analyze Windows Shellbag registry artifacts to reconstruct folder browsing activity, detect access to removable media and network shares, and establish user interaction with directories even after deletion using SBECmd and ShellBags Explorer. |
| domain | cybersecurity |
| subdomain | digital-forensics |
| tags | ["shellbags","windows-registry","sbecmd","shellbags-explorer","folder-access","user-activity","removable-media","network-shares","bagmru","dfir"] |
| version | 1.0 |
| author | mahipal |
| license | Apache-2.0 |
| nist_csf | ["RS.AN-01","RS.AN-03","DE.AE-02","RS.MA-01"] |
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.
When to Use
- When investigating security incidents that require analyzing windows shellbag artifacts
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques
Detection Gaps & Validation
- Shellbags prove Explorer-shell navigation only. Folders reached via
cmd, PowerShell, or programmatic APIs leave no Shellbag entry. Absence of a Shellbag is not absence of access — corroborate before clearing a path.
- Most-missed source:
UsrClass.dat. On Windows 10/11 the bulk of folder activity lives in UsrClass.dat (Local Settings\...\Shell\BagMRU), not NTUSER.DAT. Parsing only NTUSER drops the majority of evidence; run SBECmd against both hives.
- Timestamp/timezone pitfall: the embedded shell-item dates are local-time DOS dates with 2-second granularity, while
CreatedOn/ModifiedOn/AccessedOn reflect view-setting changes, not necessarily a visit. Do not treat them as UTC and do not equate them with first/last access without correlation.
- Batch updates: Explorer can rewrite many Shellbag entries at shutdown, collapsing distinct visits into one timestamp.
- Anti-forensics: deletion of
BagMRU subtrees or whole-hive replacement. Recover from VSS and replay .LOG transaction files for dirty hives.
- Validate / cross-corroborate: tie removable/network paths to USBSTOR + MountPoints2 (volume serials), LNK/Jump List targets, RecentDocs, and
$MFT/USN entries for the same folder. A folder that "no longer exists" should still reconcile with at least one second artifact before it anchors a finding.
