Outflank Blog Unmanaged .NET Patching

To execute .NET post-exploitation tools safely, operators may want to modify certain managed functions. For example, some C# tools use the .NET standard library to terminate their process after execution. This may not be an issue for fork&run implementations that spawn a sacrificial process, but executing in-process will terminate an implant. One could write a small .NET program that resolves and patches these functions, but we were interested in an unmanaged approach (i.e. a unmanaged implant executing managed code in-process). While our example targets System.Environment.Exit, a similar technique should work for any managed function.In January 2022, I uploaded a functional example of this approach to my personal GitHub. However, the implementation was a part of a larger project, and I've received a few questions about the technique, so I created this standalone example and writeup.Tags: dotnetRead full postThe post Unmanaged .NET Patching appeared first on Outflank.