Ironically, this was posted on the XF forums of all places.
https://xenforo.com/community/threads/using-vbulletin-3-8-is-dangerous.224887/
This is not an anti-advertisement as it might seem. I simply can't post on the company's forum because a license is required. They don't respond to my emails, so I’m writing here.
I wrote to the vBulletin company administration, informing them that a group of Russian hackers is stealing entire forums and launching them on new domains. They didn’t respond to my emails. Yes, it’s hard to believe, and I can’t prove it because from the outside, it looks like a fully functioning forum with no errors, complete with messages dating back 10 years, and it's unclear who the owner is. Yes, vBulletin could always say that the vulnerability is somewhere else, like in the hosting or other software.
But recently, the situation changed. Russian hackers completely stole the forum of the vBulletin company itself – vbulletin.org – and re-uploaded it to a new address: vborg.vbsupport.ru
https://xenforo.com/community/threads/using-vbulletin-3-8-is-dangerous.224887/