The Manhattan district attorney’s office has informed Donald J. Trump’s lawyers that it is considering criminal charges against his family business, the Trump Organization, in connection with fringe benefits the company awarded a top executive, according to several people with knowledge of the matter. If the case moves ahead, the district attorney, Cyrus R. Vance Jr., could announce charges against the Trump Organization and its chief financial officer, Allen H. Weisselberg, as soon as next week, the people said. An indictment of the Trump Organization could mark the first criminal charges to emerge from Mr. Vance’s long-running investigation into Mr. Trump and his business dealings, and raises the startling prospect of a former president having to defend the company he founded and has run for decades.