My website was infected with this pub2srv malware last week. There were advertisements showing up and what not. I did managed to remove some fishy looking websites myself but then this kept on coming, had to take some professional help in the end.
This link had helped me, looks derived from this thread itself:
https://www.getastra.com/blog/911/how-to-remove-pub2srv-malware-from-your-wordpress-opencart-website/