If McAfee doesn't appear to be installed on your device I suspect Mac Jim ID's suggestion that screening has been implemented by your network provider is probably the solution to the mystery.
You didn't mention (no reason to do so until now) whether your iPad has cellular and WiFi capability, or only WiFi. IF you have the cellular version, it is likely the two connectivity routes will have different providers, so you might be able to check by disabling one route or the other so it goes via known providers. If you have the WiFi only version you could probably still check by using phone as a hotspot.
On the other hand if your network's malware screening service thinks a certain address is a problem site, it might be smart to consider whether you really want to risk visiting it. If you think it should be safe, before you force your way through please check the site address carefully, looking for errors and potential clone-site traps like a lookalike site which mis-spel1s the name (yes, my deliberate spelling error there as an example).