A person who brings goods illegally into the country

One word substitute is Smuggler.

Importer: a person or organization that brings goods or services into a country from abroad for sale.
Exporter: a person, country, or company that sends goods or services to another country for sale.
Fraud: wrongful or criminal deception intended to result in financial or personal gain.
Smuggler: a person who illegally brings goods into the country.