The new documentary about Ashley Madison's infamous cyberattack isn't warning people away from the service ... according to one exec, it's actually boosting membership, including famous folks!

We talked with Paul Keable -- the Chief Strategy Officer for Ashley Madison -- and he tells us memberships are up in recent days thanks to "Ashley Madison: Sex, Lies, and Scandal" going #1 on Netflix. Paul figures it's partly 'cause people forgot the site exists until they saw the doc.

Paul says celebs do still use the site despite the 2015 hack that leaked many prominent people's names as allegedly having accounts. He thinks this is because they're dealing with the same issues as normies, feeling trapped in monogamy and it gives them a chance to explore in a safe space.

If ya don't know, Ashley Madison launched as a dating site for married people, and still promotes itself with the tagline ... "Life is Short. Have an affair."

Both the membership boost -- at 365K new users per month -- and celebrity involvement point to one positive in Keable's mind -- a reminder of how far the company's come since the hack.

Paul says the company now puts security at the core of all new products ... and, he says the company's managed to make itself less of a target by increasing its security capabilities.

The new Netflix doc -- one of 2 produced in recent months about the scandal -- dives into the company's business model and how the data leak affected individual users. It's a look back at how devastating the leak was on a micro and macro scale -- but, sounds like all publicity's good publicity for AM.