Forster & Garbus 10% of gross weekly income paid to Sheriff Commack, New York

This afternoon I received a letter from the Sheriff's Department stating that 10% of my Gross Weekly Income will be paid by the terms of the execution to Forster & Garbus for the balance due a of this letter which is $3,999.10. This letter is saying that a judgment was entered in Nassau County, 2nd District, Hempstead and the transcript filed on 5/18/2012. I am utterly confused by this because I do not even know what this is about.  I am contacting the NYS Attorney Generals Office on Monday and also the Sheriffs Department.  I would think that If I was being sued by anyone that I would have at least been notified BEFORE a judgment.