Unknown certificate

For almost a month, I’ve been having a message pop up anytime I try to do anything important with my phone (type in Apple ID passwords, plug in charger, delete apps, etc…). The message states that my phone “Cannot Verify Server Identity - The identity of (53-news.com) cannot be verified”. Below the text, I’m given the option of looking into the error message’s ‘Details’ or to cancel it. Choosing the ‘Details’ option reveals that the certificate was issued by “pltraffic.com” and there is no option to remove it. Pressing cancel will make the message disappear, but it will always return. I cannot find anything on the internet about this specific certificate and hope someone can shed some light on it.