I have not found a clearnet forum that is worthy of being a competitor of bitcointalk except reddit.
To be honest, I think that Lazarus group is a fictional group. It doesn't make sense for North Korea to have so talented hackers, even if they are protected by the government, it still doesn't make sense if we keep in mind the philosophy of that country. Also, Lazarus group has so much money and so many talented people, they could run their own mixer/coinjoin services instead of using someone else's.
I kind of agree with this, I think it's just a result of investigators' inability to track crimes, why not just say that these criminals are in extreme areas that they can't access. Or (random thingking), it's actually a concocted "project" to confiscate the multimillion dollar money resstrained in a mixer.