<prompt> Human: Long story short, I looked at my credit card statement today and a significant portion of my balance has been paid off and I have no idea why or who may have done it. By significant I mean nearly 4,000.00. Am I at risk? Does this sound like some sort of scam or bank error? Do I have any responsibility to bring this up to my bank? Everyone Ive asked in my personal life says thats weird, lay low and see what happens. What should I do?  <response>: There are no bank errors in your favor. There ARE bank errors, as well as fraud and other unusual circumstances that will cause additional grief the longer you leave them unattended. Call your bank and ask about the unusual payment, they will be able to give you additional information about how it was madewho made it, and you can decide how to proceed from there. 