Final answer:
The user is likely dealing with a rogue antivirus program, which falsely claims to detect viruses and then requires payment to remove them, unlike legitimate antivirus software.
Step-by-step explanation:
In the scenario described, the user is likely encountering a rogue antivirus program. This type of software masquerades as legitimate antivirus software, but instead of protecting your computer, it typically generates false alerts and prompts users to pay for a full version in order to remove nonexistent viruses. Legitimate antivirus programs do not operate this way. They will scan and remove viruses without forcing the user to purchase the software. Additionally, genuine antivirus solutions will update their virus definitions and provide real-time protection without using aggressive or deceptive sales tactics. Users should avoid interacting with these pop-ups and should immediately run a scan with a reputable antivirus tool to check for genuine threats.