What considerations should be taken when creating a WLL backdoor DLL to avoid crashes?

The DLL must be carefully written to avoid crashing Word. For example, using `MessageBox` in `DLL_PROCESS_ATTACH` caused Word to freeze. The article recommends using `WinExec` or similar lightweight calls. Also, compile with optimization flags (e.g., release mode, `/OPT:nowin98`) to keep the DLL small (3KB). DLLs generated by Metasploit's msfvenom often cause Word to crash, so custom C code is preferred.