IIRC, treasurers have a high degree of legal responsibility. HC and DWS can plausibly deny, but the longtime DNC Treasurer and weirdo Andrew Tobias is a lot more vulnerable.
Of course, the money may have come from someone like Clinton pal Donald Sussman instead of through the DNC.
The candidate and the Party Chairperson have more responsibility than the Treasurer, though ho had to know about it too.
Hillary Clinton and Debbie Wasserman Schultz can not plausibly deny this.