How to Check if Someone Edited Excel Files via Remote Access
Question details
The user wants to determine if an unauthorized person used remote desktop software to secretly access their computer and edit Excel spreadsheets.
- Product
- Microsoft Excel
- Device & OS
- Windows
- Scenario
- Suspected unauthorized system access resulting in potentially altered Excel spreadsheets and missing file history.
- Observed behavior
- Excel's recent-file history temporarily disappeared, and the user noticed TeamViewer running in Task Manager, raising fears of unauthorized remote spreadsheet modification.
Before beginning your investigation, immediately disconnect your computer from the internet (turn off Wi-Fi or unplug the Ethernet cable) to sever any active unauthorized remote connections.
Check for Active Remote Access Software
Verify if remote desktop tools like TeamViewer are installed and running in the background without your authorization.
Remote access applications allow users to view and control your computer from afar. If software like TeamViewer is running unexpectedly, someone may have established a connection to your device.
Press Ctrl + Shift + Esc on your keyboard to open the Windows Task Manager.
Navigate to the 'Processes' tab and scroll through the list to look for TeamViewer, AnyDesk, Remote Desktop, or similar applications.
If you see a remote desktop application that you did not authorize, right-click on it and select 'End task' to close the connection instantly.
Go to the Windows Control Panel, select 'Programs and Features', find the unauthorized remote access software, right-click, and select 'Uninstall'.
Review Windows Event Viewer Logs
Check the system security logs for unexpected remote logon events that could confirm unauthorized access.
Secure Your Accounts and Excel Files
Take proactive steps to lock down your system and verify the last modified dates on your spreadsheets.
Secure Your Spreadsheets with WPS Office
If you are concerned about the security of your local Excel files, consider switching to WPS Office. It provides robust document encryption, cloud backup with version history, and full compatibility with Microsoft Office formats, giving you peace of mind for free.
- 1. Download WPS Office: Download and install WPS Office Free from the official website.
- 2. Open Your Spreadsheet: Open your existing Microsoft Excel (.xlsx) file in WPS Spreadsheet.
- 3. Encrypt the File: Go to the 'Menu', select 'Document Encryption', and set a secure password to prevent unauthorized viewing or editing.
Frequently Asked Questions
Does a missing recent file history in Excel mean someone accessed my PC?
Not necessarily. While a cleared history can raise suspicions, it frequently occurs due to Windows updates, temporary user profile glitches, OneDrive syncing issues, or system optimization tools clearing temporary files.
Can I see exactly who edited my local Excel file?
If the file is saved locally on your computer's hard drive, Excel only records the 'Last Modified' timestamp and the author name tied to the active Office license. To see detailed activity logs, the file must be stored on OneDrive or SharePoint with 'Track Changes' or 'Version History' enabled.
How could someone use TeamViewer to access my computer without permission?
Unauthorized access can happen if TeamViewer is configured for 'Unattended Access' and your password was compromised, or if the program was left running in the background on an unlocked PC. Always disable Unattended Access if it is not strictly required.
How do I password protect my Excel file to stop unauthorized edits?
Open your file in Excel, go to File > Info > Protect Workbook, and select 'Encrypt with Password'. Enter a strong password. Without this password, no one will be able to open or edit the file, even if they gain remote access to your PC.
