Driver Buddy Reloaded

Table of Contents

• Driver Buddy Reloaded
  • Table of Contents
  • Installation
  • Quick Usage
    • Advanced Usage
  • About Driver Buddy Reloaded
    • Finding DispatchDeviceControl
    • Labelling WDM and WDF Structures
    • Finding and Decoding IOCTL Codes
    • Flagging Functions
    • Finding DeviceName
    • Dumping Pooltags
    • Heuristic Vulnerability Checks
  • Feature Flags
  • Testing
  • Known Caveats and Limitations
  • Credits and Acknowledgements

Installation

The install method depends on your IDA version, because the built-in plugin manager (and therefore the hcli tool and the ida-plugin.json manifest) only exists in IDA 9.0 and above. IDA 7.6 and 8.x have no plugin manager and only scan the top level of the plugins folder.

IDA 9.0+ (plugin manager / hcli)

The repository ships an ida-plugin.json manifest, so IDA 9.0+ loads the plugin from its own subdirectory. Install it with:

hcli plugin install DriverBuddyReloaded

This drops the plugin into a subdirectory of your user plugins folder (e.g. %APPDATA%\Hex-Rays\IDA Pro\plugins\DriverBuddyReloaded\ or ~/.idapro/plugins/DriverBuddyReloaded/), keeping the DriverBuddyReloaded.py entry point inside that subdirectory. This is the intended layout: IDA reads the manifest, loads the declared entry point from the subdirectory, and puts the subdirectory on sys.path so the entry point can import the sibling DriverBuddyReloaded package. You do not need to move DriverBuddyReloaded.py to the top level.

Verify the install with hcli plugin status, then launch IDA and confirm the plugin appears under Edit -> Plugins (check the Output window for any Python errors at startup).

To install from a local checkout for testing (e.g. after your own changes), run hcli plugin install . from the repository root; hcli plugin lint . validates the manifest/layout first.

IDA 7.6 / 8.x (manual copy)

These versions have no plugin manager, so an hcli-installed subdirectory plugin will not be picked up. Copy the DriverBuddyReloaded folder and the DriverBuddyReloaded.py script file directly into the top level of the IDA plugins folder, for example:

• %APPDATA%\Hex-Rays\IDA Pro\plugins\
• C:\Program Files\IDA Pro 8.4\plugins\
• ~/.idapro/plugins/

The resulting layout is plugins\DriverBuddyReloaded.py alongside plugins\DriverBuddyReloaded\ (the package folder).

Notes

If your IDA is configured for Python 2, run the idapyswitch binary (located in IDA's folder) to switch it to Python 3.

NOTE: Driver Buddy Reloaded runs on IDA 7.6+, 8.x (including 8.4) and 9.0+ with Python 3. All version-specific IDA API differences (the removal of get_inf_structure, the ida_struct module and the idc.*struc* helpers in IDA 9.0, etc.) are handled internally by the DriverBuddyReloaded/ida_compat.py compatibility layer.

Quick Usage

To use the auto-analysis feature:

1. Start IDA and load a Windows kernel driver.
2. Go to Edit -> Plugins -> Driver Buddy Reloaded or press CTRL+ALT+A to start the auto-analysis.
3. Check the "Output" window for the analysis results, and the Driver Buddy Reloaded - Findings window that opens at the end of the run (double-click a row to jump to its address).
4. The following files are written under IDA's DB directory (all prefixed with <DRIVER_NAME>-YYYY-MM-DD-TIMESTAMP-):
   • findings.json - machine-readable findings (IOCTLs, flagged functions, device names, pooltags, call chains, heuristics, device ACL audit, symbolic links, exports audit, privileged opcodes)
   • report.html - a standalone, severity-grouped HTML report
   • pooltags.txt - dumped Pooltags in pooltags.txt format for WinDbg
   • autoanalysis.txt - the full text analysis log (mirrors the Output window)

To decode an IOCTL:

1. Place the mouse cursor on the line containing a suspected IOCTL code.
2. Right-click and select Driver Buddy Reloaded -> Decode IOCTL; alternatively, press the CTRL+ALT+D shortcut.

To reopen the IOCTLs window or findings window at any time (without re-running analysis):

• Press CTRL+ALT+I to open the IOCTLs window.
• Press CTRL+ALT+F to open the findings window.

Advanced Usage

• The vulnerable_function_lists directory contains a lists of potentially dangerous/problematic functions, Windows APIs and opcodes; a brief description on why a specific function/API has been listed is provided. You can edit the custom list including driver's specific functions.

  Note: winapi_function_prefixes will partial match to start of function name (e.g. Zw will match ZwClose, ZwCommitComplete and so on) while winapi_functions will perform exact matches only.

• In find_opcodes.py, the find_opcode_data option (default False) suppresses opcode matches that fall in data sections (issue #11). Switching it to True also surfaces raw byte matches in data; if a real opcode was missed this way, going to the reported address and re-defining the bytes as code usually recovers it. Matches are reported like every other stage (results window, findings.json, ).

About Driver Buddy Reloaded

Driver Buddy Reloaded is an IDA Pro Python plugin that helps automate some tedious Windows Kernel Drivers reverse engineering tasks. It has a number of handy features, such as:

• Identifying the type of the driver (WDM, KMDF, UMDF, WDF, Mini-Filter, Stream Minidriver, AVStream, PortCls)
• Locating DispatchDeviceControl / DispatchInternalDeviceControl functions for every driver type (a MajorFunction[IRP_MJ_DEVICE_CONTROL] store scan finds the handler even in a minifilter/WDF driver that also exposes a legacy control device, and even when the assignment lives in a helper rather than DriverEntry)
• Populating common structures for WDF and WDM drivers
  • Attempts to identify and label structures like the IRP and IO_STACK_LOCATION
  • Label calls to WDF functions that would normally be unlabeled
  • Creates an IRP_MJ_FUNCTION IDA enum and applies it to MajorFunction array slots in DriverEntry (WDM)

Finding DispatchDeviceControl

The tool can automatically locate and identify the DispatchDeviceControl routine. This function is used to route all incoming DeviceIoControl codes to the specific driver function associated with that code. Automatically identifying this function makes finding the valid DeviceIoControl codes for each driver much quicker. Additionally, when investigating possible vulnerabilities in a driver due to a crash, knowing the location of this function helps narrow the focus to the specific function call associated with the crashing DeviceIoControl code.

When the analysis is successful some subs will be renamed as follow:

• DriverEntry: the original first driver-supplied routine that is called after a driver is loaded. It is responsible for initializing the driver.
• Real_Driver_Entry: usually the function where the execution from DriverEntry has been transferred to. It is usually where the DeviceName is initialized.
• DispatchDeviceControl/DispatchInternalDeviceControl: if the tool was able to recover the functions at some specific offsets, the functions will then be renamed with the appropriate name.
• Possible_DispatchDeviceControl_#: if the tool was not able to recover DispatchDeviceControl or DispatchInternalDeviceControl, it employs an experimental searching, following the execution flow, and checking for cases where the function is loading known IO_STACK_LOCATION & IRP addresses; indicating that the function could be the DispatchDeviceControl. As it is based on heuristic, it could return more than one result, and it is prone to false positives.

Labelling WDM and WDF Structures

Several driver structures are shared among all WDM/WDF drivers. The tool is able to automatically identify these structures, such as the IO_STACK_LOCATION, IRP, and DeviceObject structures and can help save time during the reverse engineering process and provide context to areas of the driver where these functions are in use.

Finding and Decoding IOCTL Codes

While reversing drivers, it is common to come across IOCTL codes as part of the analysis. These codes, when decoded, reveal useful information and may draw focus to specific parts of the driver where vulnerabilities are more likely to exist.

By right-clicking on a potential IOCTL code, a context menu option is presented (alternatively using the Ctrl+Alt+D shortcut when the cursor is on the line containing a suspected IOCTL code) and can be used to decode the value. This will print out a table with all decoded IOCTL codes. By right-clicking on a decoded IOCTL code, in the disassembly view, it's possible to mark it as invalid; this will leave any non-IOCTL comment intact.

• The decoded IOCTLs are printed to the Output window and listed in the severity-coloured IOCTLs window; after auto-analysis they are also recorded in findings.json / report.html.

Auto-analysis additionally runs a multi-strategy scan over identified dispatcher functions to discover IOCTLs automatically, without requiring manual cursor placement. For each dispatcher it uses the Hex-Rays decompiler (when available) to read switch-case labels and ==/!= comparison constants directly from the reconstructed control flow, falling back to IDA's switch-table metadata and then to a raw immediate-operand scan. The decompiler path recovers codes that never appear verbatim in the disassembly - e.g. drivers whose dispatcher the compiler emitted as a jump table (only the table base/bound survive as immediates) or as a binary-search comparison tree (intermediate codes survive only as deltas). On a representative corpus this raised recovery from 7/28 to 28/28 (HEVD) and 4/17 to 17/17 (ALSysIO64) with no false positives.

Flagging Functions

Driver Buddy Reloaded has lists of C/C++ functions, opcodes and Windows APIs (defined in the vulnerable_function_lists directory) that are commonly vulnerable or that can facilitate buffer overflow conditions. All found instances are reported back during the auto-analysis and can help while looking for possible user-controlled code paths reaching sensitive functions.

Finding DeviceName

The tool automatically attempts to find the drivers registered device paths (DeviceName), if no paths can be found by looking at Unicode strings inside the binary, then the analyst can manually try to use Madiant's FLOSS in an attempt to find obfuscated paths.

Dumping Pooltags

During the auto-analysis, the tool also dumps the Pooltags used by the binary in a format that works with pooltags.txt. The output can then be copy-pasted at the end of the file and later picked up by WinDbg.

• A DriverName.sys-DATE-TIME_STAMP-pooltags.txt file, containing all the dumped Pooltags, will be written under IDA's DB directory.

Heuristic Vulnerability Checks

The heuristics.py module runs after call-chain tracing and examines each dispatcher and the functions it transitively calls - so the per-IOCTL handlers, not just the dispatcher prologue, are analysed. Callee matching is import-aware (an imported call cs:__imp_<Name> matches the same name as a local call). It emits findings in the heuristic category (privileged-instruction findings use the opcode category):

These are lead generators, not confirmed vulnerabilities. Treat HIGH/CRITICAL findings as starting points for manual review.

Feature Flags

All optional analysis stages are controlled by DriverBuddyReloaded/config.py. Edit the Feature class to enable or disable them:

Testing

Three layers, from fast to thorough:

• Pure-Python regression (no IDA required) - covers all logic that does not touch the live database:
  root@kitploit:~

  python tests/test_dbr.py
  DBR_SDK=900 python tests/test_dbr.py   # simulate the IDA 9.0 import paths
  

• Cross-version smoke - runs the full pipeline under IDA 7.6 SP1, 8.4 and Free 9.3 against a matrix of real .sys files and prints a pass/fail table: pwsh tests/run_cross_version.ps1.
• Golden-output regression (the false-positive / false-negative guard) - pwsh tests/run_golden.ps1 re-runs the full analysis on a pristine copy of each reference driver in tests/drivers/ and compares the findings to the committed tests/drivers/<driver>.golden.json baseline (order-insensitive on category, title, severity and IOCTL code/method/access). Any added finding (false positive), missing finding (false negative) or severity change fails the run. Regenerate a golden only when a change intentionally alters findings, and review the diff. Goldens are tied to the IDA decompiler build they were captured with (8.4), so run the regression with that version.

Known Caveats and Limitations

• IOCTL candidates are validated against the CTL_CODE structure by _is_valid_ctl_code(): the DeviceType field (bits 31-16) must be non-zero, and the value must not match a known NTSTATUS code or the 0xFFFFFFFF (DWORD)-1 sentinel (a comparison constant seen inside real dispatchers, e.g. WinRing0). This rules out loop counters, small immediates and error codes while preserving all valid IOCTLs including vendor-defined device types (0x8000+). The same filter is applied to all four discovery paths: the IoControlCode xref scan and the three dispatcher collectors (decompiler ctree, IDA switch-table recovery, and the raw immediate-operand scan).
• Risk scoring and call-chain tracing are heuristic, name-based lead generators, not dataflow analysis; treat High/Critical findings as places to look first, not as confirmed vulnerabilities. Feature toggles live in DriverBuddyReloaded/config.py.
• Experimental DispatchDeviceControl searching works only for x64 drivers
• In find_opcodes.py, the find_opcode_data option (default False) suppresses opcode matches that fall in data sections. Switching it to also surfaces raw byte matches in data, which is prone to false positives; if a real opcode was missed, going to the reported address and re-defining the bytes as code usually recovers it. Matches are reported like every other stage (results window, , ).

Credits and Acknowledgements

• Created in 2021 by Paolo Stagno aka @Void_Sec:
• Risk-scoring and reporting ideas adapted from Driver Buddy Revolutions by Juan Sacco.
• DriverBuddy was originally written by Braden Hollembaek and Adam Pond of NCC Group.
• Using Satoshi Tanda's IOCTL decoder.
• The WDF functions struct is based on Red Plait's work and was ported to IDA Python by Nicolas Guigo, later updated by Braden Hollembaek and Adam Pond.
• Using Sam Brown's F-Secure win_driver_plugin to retrieve device name and pool tags, specifically Alexander Pick fork.
• The original code for adding items to the right-click menu (and possibly some other random snippets) came from 'herrcore'.
• Proudly developed using PyCharm for Open Source development by JetBrains