The U.S. Securities and Exchange Commission (SEC) has issued an updated warning about fraud artists posing as regulators.

The SEC’s Office of Investor Education and Advocacy Friday published an updated investor alert to warn investors about the threat posed by fraudsters that use correspondence purporting to be from the SEC as part of a scam. It says the phony letters may include use of the SEC seal, and purport to be signed by SEC inspector general, Carl Hoecker.

“Fake SEC correspondence may look authentic and include a link to the SEC’s website,” it notes. “Email messages may appear to come from SEC email accounts. Letters may imitate the official SEC seal and forge signatures of SEC officials.”

The regulator reiterates that it does not facilitate the settlement of unpaid trading fees, assist with the purchase or sale of securities, or participate in fund transfers. It also stresses that it does not approve or endorse particular securities, issuers, products, services, professional credentials, firms, or individuals.

The alert also spells out the sorts of things that the SEC does not do in its legitimate correspondence. And, it advises recipients of purported SEC communications to ensure they contact the regulator directly to verify its authenticity, rather than calling the number, or using an email address, provided in the correspondence.