Just caught a name that was used for spam. How do I clean it up?

[legal]

Hello all: I just caught a name that I need, it is the acronym for my full business name. An LLLL.com. Paid fair price...always too much, eh?? Anyway. I went into this with my eyes open. The domain has a history, as does the previous registrar and host, of spamming. All three show up on...