• Not really an evasion medium, more of a built-in way to access unmanaged code (ie: C/C++) via managed code (C#)
• Import Dlls and create functions signatures for the function you wish to call. Below is an example of using Pinvoke so I can call CreateThread in C#.

[DllImport("kernel32.dll")]
static extern IntPtr CreateThread(
	IntPtr lpThreadAttributes,
	uint dwStackSize,
	IntPtr lpStartAddress,
	IntPtr lpParameter,
	uint dwCreationFlags,
	IntPtr lpThreadId);

• To generate the function signature, refer to pinvoke.net or read the microsoft documentation on the method call and yolo the determining of the datatypes.

Pros

• Easy, simple access to any API exported by a DLL

Cons

• An entry is made in the import address table (IAT) of the executeable, making it super easy to get flagged by AV & EDR
• The APIs we import are potentially hooked