Hard for me go determine, since I've never lived in/ even been to Malden or Salem (outside of driving through the Malden), so I cannot really gauge.

I'll put it this way, Vernon Hills is far from the nicest place in the City of Worcester, however, at the same time, it's certainly not the worst either. If you've lived in not particularly wealthy areas of New England (with triple deckers and the like), you will probably be in your element.

My disclaimer is that I've only lived in North Worcester, and I don't have any friends and family from Vernon Hill. The closest thing to that is that my great-grandparents lived there and my grandfather grew up there, but he was born in 1927, and she died in the 80s, and the neighborhood has changed since then.

I think you'll be fine, so long as you take the normal living-in-the-city precautions.