winchecksec

winchecksec performs static detection of common Windows security features.

The following security features are currently detected:

• ASLR:
  • /DYNAMICBASE with stripped relocation entries edge-case
  • /HIGHENTROPYVA for 64-bit systems
• Code integrity/signing:
  • /INTEGRITYCHECK
  • Authenticode-signed with a valid (trusted, active) certificate (currently unsupported on Linux)
• DEP (a.k.a. W^X, NX)
• Manifest isolation via (/ALLOWISOLATION)
• Structured Exception Handling and SafeSEH support
• Control Flow Guard and Return Flow Guard instrumentation
• Stack cookie (/GS) support

Building

winchecksec depends on pe-parse and uthenticode, which can be installed via vcpkg:

$ vcpkg install pe-parse uthenticode

NOTE: On Windows, vcpkg defaults to 32-bit builds. If you're doing a 64-bit winchecksec build, you'll need to explicitly build the dependencies as 64-bit:

$ vcpkg install pe-parse:x64-windows uthenticode:x64-windows

Building on Linux

$ git clone https://github.com/trailofbits/winchecksec.git
$ cd winchecksec
$ mkdir build
$ cd build
$ cmake -DCMAKE_BUILD_TYPE=Release ..
$ cmake --build .
$ ./build/winchecksec

Building on Windows

> git clone https://github.com/trailofbits/winchecksec.git
> cd winchecksec
> mkdir build
> cd build
> cmake ..
> cmake --build . --config Release
> .\Release\winchecksec.exe C:\Windows\notepad.exe

Usage

As a command-line tool, winchecksec has two output modes: a plain-text mode for easy reading, and a JSON mode for consumption in other programs. The plain-text mode is the default; JSON output is enabled by passing --json or -j:

> .\Release\winchecksec.exe C:\Windows\notepad.exe

Dynamic Base    : "Present"
ASLR            : "Present"
High Entropy VA : "Present"
Force Integrity : "NotPresent"
Isolation       : "Present"
NX              : "Present"
SEH             : "Present"
CFG             : "NotPresent"
RFG             : "NotPresent"
SafeSEH         : "NotApplicable"
GS              : "Present"
Authenticode    : "NotPresent"
.NET            : "NotPresent"

> .\Release\winchecksec.exe -j C:\Windows\notepad.exe

[{
   "path": "C:\\Windows\\notepad.exe",
   "mitigations": {
      "dynamicBase": {
         "presence": "Present",
         "description": "Binaries with dynamic base support can be dynamically rebased, enabling ASLR."
      },
      "rfg": {
         "description": "Binaries with RFG enabled have additional return-oriented-programming protections.",
         "presence": "NotPresent"
      },
      "seh": {
         "description": "Binaries with SEH support can use structured exception handlers.",
         "presence": "Present"
      },
      // ...
   }
}]

winchecksec also provides a C++ API; documentation is hosted here.

Hacking

winchecksec is formatted with clang-format. You can use the clang-format target to auto-format it locally:

$ make clang-format

winchecksec also comes with a suite of unit tests that use pegoat as a reference for various security mitigations. To build the unit tests, pass -DBUILD_TESTS=1 to the CMake build.

Statistics for different flags across EXEs on Windows 10

Prevalence of various security features on a vanilla Windows 10 (1803) installation:

aslr	authenticode	cfg	dynamicBase	forceIntegrity	gs	highEntropyVA	isolation	nx	rfg	safeSEH	seh
79%	37%	49%	79%	3%	65%	43%	100%	79%	6%	25%	91%