I own a website. Now today I find that when I load the site, Chrome shows "waiting for xxx.com" and some other unknown sites.
I never added content or links from these sites.
The website is running on WordPress.
What can be the cause of this issue?
It looks like your website is hacked / compromised and the attacker must have injected some malicious script into your website index for monetary gain through ads or for other profits. There is also a possibility that the source website from where it is loading the content is also hacked / compromised. What I can suggest you is:
I would suggest you to create a backup of the complete website, Freshly install the latest version of Wordpress and then restore / import the db (there is still the possibility of the code hidden in the database but I have found very rare cases where this happens)
More details can be found here.
Open your browser's development window, and look for requests in the network tab. This could be a WordPress plugin loading something from a 3rd party, it could be your browser preloading links or it could be one of your browsers add-ons/plugins/extensions loading something. It's nearly impossible to say with the information provided.
You could also try viewing the source of the page in question, although requests may also be triggered by scripts located elsewhere on the site.