However, isn't 'cracker' = 'malicious hacker'?
The exact definition of a cracker as provided by the jargon file is "One who breaks security on a system." However it also notes that a hacker is, among other things, "A person who enjoys exploring the details of programmable systems and how to stretch their capabilities."
It's easy to see how the two definitions can overlap. If I break the security of a system which I am authorized to perform a security audit on, which am I? This isn't a very important difference, the main distinction is more or less based on legality (although there are several exceptions).
This may all sound very trivial, it's just a word right? Consider if in a year the major media outlets started using the term "programmer" to refer to computer criminals. Why change the meaning of a word because some reporters don't know what they're talking about?