There are 2 repositories under thread-hijacking topic.
VAC-proof 32bit DLL injector written in C++, using memory mapping and thread hijacking techniques
Various Process Injection Techniques
manual mapping injector
Process inject technique "Thread hijacking" via csharp
A proof-of-concept C# project that can inject a DLL into a process by hijacking its main thread.
Windows Injector examples in c/pp
Some examples and methods for performing a DLL injection in Win Env
Code for example Thread-Hijacking method