I seriously doubt that your employer is trying to scam you while connecting to their wifi network... 😕
As long as you haven't jailbroken your iPad, you can't have any malware. If you have jailbroken it, you could have downloaded a malicious app, and that might be what is triggering this message.
If you haven't jailbroken your iPad, it's definitely not a virus. Your employer, or the ISP (internet service provider) that provides the service, must be using a tool to scan for suspicious network traffic, and that tool has a problem with false positives. Unfortunately, this sort of thing happens all the time. Devices that don't have viruses - even devices, like the iPad, that can't have a virus - have their internet service blocked inappropriately, for no good reason. You'll need to take this up with your employer's tech support, who may then need to take it up with their ISP's tech support.