Question Plesk was inserted malicious script code

[kukaykk]

My server has Plesk installed to administer Hosting. But Plesk is crashing, can't create a new Domain.
Initially, the cause was determined that the server or Plesk was infected with malicious code or a virus. “It” is injecting advertising scripts into my websites, I have checked the code of the websites and determined that there is no code directly attached to the Code Website. I have also created a new blank Site, and this Site is also inserted with the Promotion code As shown in the attached image.
Has anyone encountered this situation?

 

[vikK]

Scan your computer and browser extensions if you are facing this issue on a complete new site.

 

[Bitpalast]

The symptom is typical for malicious browser add-ons. When you open the website on a different machine that is not infected, it will probably not contain the advertisement sections.