[khedoros1]

It's heavily context-dependent for me. Based on the situation, I'd expect it to be:

- A network intrusion

- A cool, clever piece of programming, without any other expectation of quality besides "it works"

- A "clever" (in a bad way), ugly, and (hopefully) temporary mess, done knowingly because of time constraints

- A program, usually put together quickly, to do a specific job

"Hacked into" would imply the first meaning, the others could be differentiated with further adjectives "clean", "dirty", "ugly", "cool", "quick", etc. Whether it's positive or negative really depends on the situation.