The Kernal is the low-level “operating system” of the Commodore 64. The functions it provides are the basis for higher level routines in Basic and most other software running on Commodore’s 8-bit machines. In case of the C64 it comes in the form of an 8k ROM chip or as part of a 16k ROM chip in later versions. So the good news is, the Kernal is immune to corruption though any kind of malware. The bad news is, there is no easy way of updating or replacing it although Commodore’s original Kernal leaves a lot of room for improvement.