Android users may encounter fake virus warning pop-ups, often triggered by visiting malicious websites. To remove these pop-ups, users should close all browser windows, force stop the active browser, and clear its cache. For prevention, users should keep their Chrome app updated, disable pop-ups and ads, and enable prompts for automatic downloads. While the risk of actual viruses on unrooted Android devices is low, users should uninstall suspicious apps and use malware detection apps like Malwarebytes and CCleaner to ensure their devices are malware-free. If a virus warning appears outside the browser, it may indicate a compromised browser due to a malicious add-on.