1. A computer-implemented method for determining whether computer code contains malicious code, said method comprising the steps of: identifying computer code having a decryption loop and a body; performing a dead code elimination procedure on the computer code; noting an amount of dead code eliminated during the dead code elimination procedure; responsive to the amount of dead code eliminated during the dead code elimination procedure exceeding a preselected dead code threshold, declaring a suspicion of malicious code in the computer code; optimizing the decryption loop to produce optimized loop code; performing a malicious code detection procedure on the optimized loop code; and responsive to the malicious code detection procedure detecting malicious code in the optimized loop code declaring that the computer code contains malicious code.