Our cat does that when she gets too wound up, or if she's been alone too long and wants attention.

She's also skittish, the perfect example of a 'scaredy cat'. We got her as a kitten, and she came from a good home (friends), so we figure it's just her personality. I'm the only one who can pick her up, although she likes to sleep on available laps whenever possible.

 

Probably a dumb question, but you don't have any fleas or similar small bugs running around the house, do you? Perhaps ones that your cat can see crawling around on your skin?

None of my cats have ever outright attacked me, but sometimes they stalk and attack small insects that are too tiny for me to see easily. I've been "caught in the crossfire" on a few occasions.

Most definitely DO NOT hit the cat. Regardless of what's causing its odd behavior, hitting it is likely to do far more harm than good. If anything, just yell at it loudly immediately after the undesirable behavior.

Oh yeah, since it's 9 years old, could it be losing some of its eyesight? Sometimes older cats get more defensive and cranky because of physical impairments like bad vision. One of my cats died of fatty liver disease, and it was real grumpy during the later stages of the illness.