I can't access virtualbox.org any more, they now show an error page saying "Payment Required", with status code 402.
Interestingly, if I change my user agent to "curl/7.70.0", I can browse virtualbox.org again.
They seem to be unhappy with my user agent specifically:
curl -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36" https://www.virtualbox.org
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>402 Payment Required</title>
</head><body>
<h1>Payment Required</h1>