Stopping Harmful Interference in Elections for a Lasting Democracy Act or the SHIELD Act This bill establishes a duty to report election interference from foreign entities, applies existing campaign advertising requirements to online advertisements, and generally limits political spending and election interference by foreign entities. Specifically, a political committee must report certain foreign contacts involving an offer of unlawful election assistance to the Federal Bureau of Investigation and the Federal Election Commission. The bill establishes criminal penalties for violations of these requirements. Existing requirements for political advertisements and electioneering communications apply to internet and digital advertisements, including requirements related to disclosures and contributions. Additionally, large online platforms must maintain a public database of certain political advertisements. The bill places limitations on political spending by foreign entities. Specifically, foreign entities may not (1) contribute to campaigns related to ballot initiatives and referenda, or (2) make disbursements for certain internet activity referring to a candidate or a political issue. A candidate is prohibited from offering to share nonpublic campaign information with certain foreign entities. The bill also prohibits (1) the dissemination of false statements regarding federal elections or public endorsement, or (2) the intentional hindering of voting or registering to vote. The bill establishes criminal penalties and a private right of action with respect to these prohibitions.