There is no definition of shrink-wrap agreement under Brazilian laws. When dealing with a shrink-wrap agreement, Brazilian jurists tend to use the term in English or "contrato (do tipo) shrink-wrap" or "acordo (do tipo) shrink-wrap".
There are multiple definitions - click on the translation that matches your context.
an agreement that appears on the outside packaging of a product granting formal authority to use the product which is agreed to when the package is opened
"Sublicense" means an executed agreement or shrink-wrap agreement or electronic license that an end user consents to by performing a physical act.