Usually and investor makes a Due Diligence in the company. Depending on the stage of the company, investor profile, this due diligence can be a formal one, wher

Usually and investor makes a Due Diligence in the company. Depending on the stage of the company, investor profile, this due diligence can be a formal one, where you hire external auditors to make the process or in a more early-stage phase you can do VC firm (or angel) makes the due diligence themselves. Either way, at least in Brazilian Law (I work with VC in Brazil, but I imagine there is something similiar in USA), we have a "Hidden Liabilities" clause in our termsheet. It says that anything prior to the investors investiment is liable to the founders only.