How to Collect a HAR File and HTTP Error Logs Using Firefox

Products

• Carbon Black App Control (formerly Cb Protection)
• Carbon Black Cloud Endpoint Standard (formerly Cb Defense)
• Carbon Black Cloud Enterprise EDR (formerly Cb Threathunter)
• Carbon Black EDR (formerly Cb Response)

Issue/Introduction

Capture diagnostic logs from a web browser for UI troubleshooting using Firefox

Environment

• Mozilla Firefox: All Supported Versions

Resolution

1. Press F12 to open the Debug pane.
2. Navigate to the Network tab.
3. Recording should start automatically or Click on the Pause/Resume Recording button to start recording.
4. Reproduce the action in question.
5. Right click on the recorded events > Save All as HAR
6. Check for and save HTTP Error details
   1. For any errors observed above, note the Request URL and HTTP error number (4## or 5##)
   2. Select the Console tab
   3. Locate the error number tied to the Request URL
   4. Right-click matching error and click "Save As..."
   5. Set name of file, including at least HTTP error number, and save file to your computer

      Example
      Original filename: defense-prod05.conferdeploy.net-1646930859819.log
      
      Updated filename: 400_defense-prod05.conferdeploy.net-1646930859819.log

7. Attach the HAR file and HTTP Error file to the case

Additional Information

• To stop recording click on the trashcan at the top left of the Debug pane.
• If a graph appears instead of the events click the Back button on the left side of the Debug pane.
• All credentials and session cookies within a HAR file should be removed before sharing with Carbon Black
  • The HAR file is a text file, it can be opened in a text editor and searched for the SESSION cookie value and replaced with <REDACTED>
  • This can also be done for passwords and API tokens if they were part of the recording
  • It's also recommended to logout from the Carbon Black session after recording a HAR session. This is a precaution that should invalidate session IDs if any were missed.