HBO’s Silicon Valley, which just finished its fourth season, tells the story of Pied Piper — an early stage data compression startup — and its rivalry with the tech giant Hooli. Over the course of the show, Pied Piper and Hooli have become well-known and highly recognized tech brands, even though neither company exists in real life. HBO has even created Pied Piper and Hooli websites and put up billboards along Highway 101 in the real Silicon Valley (as seen above) for non-existent Hooli-sponsored events.

But with real domain names come real headaches, including phishers abusing those domains. Believe it or not, there are scammers out there trying to use Hooli.com and PiedPiper.com email addresses in the From fields of their fraudulent messages.

After all, who could resist an offer from Gavin Belson (gavin.belson@hooli.com) for free tickets to Hoolicon? Or a free e-book on the “Conjoined Triangles of Success” from “Action” Jack Barker (action.jack@hooli.xyz)? Wouldn’t you click on a link or sign up for an account, if only to see what happens next?

This is not a hypothetical threat. Since ValiMail started monitoring these domains last month, we have detected thousands of messages that appeared to be sent from the Hooli and Pied Piper domains. All of these messages were sent by scammers.

But because ValiMail is now protecting these domains, none of these fake messages are reaching their intended recipients. Only authenticated messages — those sent by the “real” Pied Piper and Hooli (in other words, by HBO) — will now be delivered.

So next time you receive an email from Richard Hendricks (richard.hendricks@piedpiper.com) asking you to participate in the next Pied Piper beta, you can just check the From address and be assured that it’s legitimate. That’s a lot easier than getting a Weissman score of 2.89.

And for those of you who run companies — in Silicon Valley or elsewhere — perhaps the lesson is this: If these fake companies’ domains are being abused, it’s likely your real company’s domains are too.

Top photo: Hoolicon billboard in Santa Clara, California, via Imgur.

The CTO and co-founder of Valimail, Peter is an MIT- and Stanford-trained technologist who has worked in a variety of software verticals including security, enterprise, email, and video. He has built products and teams at a number of large technology companies such as RSA Security and Perot Systems, as well as at small startups like Tout, Securant, and Swapt.