Maybe have a look in Gwern’s dark net market archives , they may have some hacker forums included. https://www.gwern.net/DNM-archives

Thanks this is helpful. It's limited to 2013-2015 but links to the following U of Arizona study which references an archive of IRC channels between 09/2016 and 01/2018: https://www.gwern.net/docs/sr/2018-du.pdf

Hackers only hang out on the Dark Web in movies.

They are barely even on the Deep Web.

So I take it your view is that it would be very difficult - if not impossible - to ever archive most communications of blackhats regarding exploits?

The opposite.

I'm saying they are on the open web.

Their sites are indexed by Google.

But there is a Survivor bias. All the article you read are going to concentrate on easy to access material. So how much is deep web is hard to guess. But I haven't heard of much on the Dark Web.