What happens if I miss 1099 MISC while filing taxes?

I have received 1099 MISC for online income of little over 600 dollars. Later I learned that I was not eligible to receive this side income due to a legal issue. As I understand, 1099 income below 600 dollars is not taxable. Since I earned only a few dollars more than that amount, will IRS issue an audit if I do not include 1099 misc? If they do, will they audit previous years as well?