Stop Business with Terrorists Act of 2008 - Subjects the parent company of a foreign entity that violates certain executive orders prohibiting certain business transactions with Iran (or other such prohibitions imposed on Iran under the authority of the International Emergency Economic Powers Act) to penalties to the same extent as if the parent company had engaged in such violations. Provides that such prohibitions and penalties shall not apply to a parent company of an entity on which the President imposed a penalty for a violation that was in effect on the date of the enactment of this Act if the parent company divests or terminates its business with such entity not later than 90 days after such date of enactment.