How to Debug a Blue Screen of Death

Originally published by ThreatLocker.

What is a Blue Screen of Death?

The Blue Screen of Death (BSOD), a stop error or system crash, is an error screen displayed on Windows computers following a fatal system error. This error causes the system to stop completely, requiring a restart to temporarily resolve the issue.

What Causes a Blue Screen of Death?

1. Hardware Failures: Issues with RAM, hard drives, or other hardware components.
2. Driver Problems: Corrupt or outdated drivers can cause conflicts.
3. Software Issues: Incompatible software, especially system-level software, can lead to crashes.
4. Overheating: Excessive heat can cause hardware components to fail.
5. Overclocking: Pushing hardware beyond its specifications can lead to instability.

How to Open and Debug a Blue Screen of Death

• How to view Blue Screen of Death (BSOD) information
  • On-Screen Information: When a BSOD occurs, it displays an error code and a brief description. Note this information as it provides clues to the underlying issue.
  • Minidump Files: Windows saves crash information in minidump files located in the `C:\Windows\Minidump` directory.
• To analyze the cause of a BSOD, follow these steps:
  • Install Windows Debugging Tools:
    • You can download the Windows Debugging Tools from the Windows SDK.
    • Select only the Debugging Tools.
• Set Up the Debugging Environment:
  • Launch `WinDbg` (Windows Debugger).
  • Configure the symbol path to help the debugger understand the Windows components involved. Use the following symbol path:
    • Cmd line > SRV*c:\symbols*http://msdl.microsoft.com/download/symbols
• Open Minidump File:
  • In `WinDbg`, go to `File > Open Crash Dump` and navigate to the minidump file (`.dmp`).
  • Load the dump file. The debugger will start analyzing the file and load the necessary symbols.
• Analyze the Dump File:
  • Use the `!analyze -v` command in the command window for detailed analysis.
  • Look for the "BugCheck" code and the associated "MODULE_NAME" and "IMAGE_NAME" which point to the potential cause.
• Interpreting Results:
  • BugCheck Code: Provides an error code indicating the type of error.
  • Causing Module: Identifies the driver or component that likely caused the crash.

Simulating a Blue Screen of Death

Simulating a Blue Screen of Death (BSOD) can be helpful for testing purposes. Here’s a step-by-step guide to simulate a BSOD on a Windows machine, followed by how to capture screenshots during the process.

Method 1: Using the "NotMyFault" Tool

• Download notmyfault.exe:
  • Download "NotMyFault" from the [Microsoft Sysinternals website] (https://docs.microsoft.com/en-us/sysinternals/downloads/notmyfault).
• Unzip and execute the tool:
  • Unzip the downloaded zip file and run `NotMyFault.exe`.
• Trigger a BSOD:
  • In the notmyfault.exe, select the “Crash” tab.
  • Click on “Do Bug” to trigger a BSOD.

Method 2: Forcing a Blue Screen of Death via Registry and Keyboard Shortcut:

This method involves modifying the Windows registry and using a keyboard shortcut to trigger a BSOD.1. Modify Registry:

• Open `regedit` and navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\kbdhid\Parameters
  • Create a new `DWORD` value named `CrashOnCtrlScroll` and set its value to `1`.
• Restart the Computer:
  • Restart your computer for the changes to take effect.
• Trigger the BSOD:
  • After rebooting, you can force a BSOD by holding the `Ctrl` key on the right side of the keyboard and pressing the `Scroll Lock` key twice.

Debugging the Blue Screen of Death

Once you have simulated a Blue Screen of Death (BSOD), you can analyze the crash dump using WinDbg.

• Open WinDbg:
  • Launch `WinDbg` and set the symbol path: **Cmd > SRV*c:\symbols*http://msdl.microsoft.com/download/symbols
• Load the Minidump File:
  • Go to `File > Open Crash Dump` and select the minidump file from `C:\Windows\Minidump`.
• Analyze the Dump:
  • Use the `!analyze -v` command to get detailed information about the crash.

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References

[Microsoft Sysinternals - NotMyFault]
[Microsoft Docs - WinDbg Preview Installation]
[How to Trigger a BSOD]
[Microsoft Docs: WinDbg Preview - Installation]
[How to Fix Blue Screen of Death (BSOD)]
[YouTube: How to Use WinDbg to Analyze a BSOD]