Term for a firm used as a public front to hide an illegal operation

Question

What do you call a firm used as a public front to hide an illegal operation?

This would be a term for, for e.g.,

• A law firm used to hide a money laundering operation;
• A DVD corner shop where pirated films can be traded;
• A chemical plant concealing a large meth lab;
• A museum where secret slave auctions are held;
• A motorcycle shop where illegal guns are sold; and
• A legal casino where illegal gambling is secretly held in a back room club.

Answer 1

Front (in sense 3, “A person or institution acting as the public face of some other, covert group [eg] Officially it's a dry-cleaning shop, but everyone knows it's a front for the mafia”, or sense 10, “An act, show, façade, persona: an intentional and false impression of oneself”) or front organization (“any entity set up by and controlled by another organization, such as intelligence agencies, organized crime groups, banned organizations, religious or political groups, advocacy groups, or corporations”) probably are the best terms for the several operations mentioned in the question, but some related terms include

• dummy corporation (“an entity created to serve as a front or cover for one or more companies”),
• shell corporation (“a company which serves as a vehicle for business transactions without itself having any significant assets or operations”),
• Straw owner (“a person who owns property legally or has the legal appearance of owning something but does so on behalf of another, sometimes for a fee, and typically solely to hide the identity of the effective owner. Most instances of straw ownership are legal, but the arrangement is sometimes made for nefarious, illegal purposes”)
• cover (sense 14, “A persona maintained by a spy or undercover operative”)

Answer 2

My try is for "shell corporation". Another one try is for "front company".

An article on Wikipedia states:

A shell corporation is a company which serves as a vehicle for business transactions without itself having any significant assets or operations. Shell corporations are not in themselves illegal and have legitimate business purposes. However, they are a main component of the underground economy, especially those based in tax havens. They may also be known as international business company, personal investment companies, front companies, or "mailbox" companies.

A quote from Urban dictionary calls it "front":

A legitimate business used to launder or cover up money being made from alternative sources

and provides an example of it's usage: "The coffee shop is a front. That's why all the homies hang there."