This paper fundamentally shifts my threat model from one focused on external attacks to one centered on internal, trustworthy components. It demonstrates that a trusted program, like a compiler, can be compromised during its creation, allowing it to produce other programs that are also infected. This is a "Trojan horse" attack at the *source* level, where the tool of trust (the compiler) is itself the vector of compromise.

Therefore, my new defense strategy is **source-level integrity verification**. I will no longer trust a program simply because I trust the people who wrote it; I must verify the integrity of its source code and the tools used to build it. I will implement a process where the source code of critical system components is cryptographically signed, and the compiler itself is verified as a trusted entity. This ensures that a bug or a Trojan horse in the compiler cannot propagate silently, and the integrity of the entire system is maintained.