215 ILCS 5/121-4
The failure of an insurer transacting insurance business in this State to obtain a certificate of authority does not impair the validity of any act or contract of that insurer nor does it prevent that insurer from defending any action in any court of this State. However, no insurer transacting insurance business in this State without a certificate of authority may maintain an action in any court of this State to enforce any right, claim or demand arising out of the transaction of that business until the insurer has obtained a certificate of authority.
If any such unauthorized insurer fails to pay any claim or loss within the provisions of such an insurance contract, any person who assisted or in any manner aided directly or indirectly in the procurement of the insurance contract shall be liable to the insured for the full amount of the claim or loss as provided in that insurance contract.
215 ILCS 5/121-4