Crack Down on Dark Money Act This bill prohibits tax-exempt 501(c)(4) social welfare organizations from using more than 10% of their total expenditures on covered political expenditures (i.e., direct or indirect expenditures for an exempt function, including influencing or attempting to influence the selection, nomination, election, or appointment of any individual to any federal, state, or local public office or office in a political organization, or the election of presidential or vice-presidential electors, whether or not such individual or electors are selected, nominated, elected, or appointed). The bill also requires a social welfare organization that spends funds on political intervention to publicly disclose the name and address of any contributor donating $5,000 or more to such organization. The term political intervention includes advocacy for the election, defeat, nomination or recall of a political candidate, the making of contributions to a political campaign, communications to the electorate about political candidates, and political use of resources.