Smartphones contain a lot of sensitive information, so it's important to make sure they are secure. Here are some signs that your phone may have been compromised. 1. Your Phone Is Slower Than Usual If your phone is taking longer to do basic tasks such as loading pages, it could have been infected with malware. Malware works behind the scenes, draining your phone's processing resources, resulting in sluggish performance. 2. High Data Usage If you see an unusually high spike in your data usage, that could be a sign something isn't right. High data usage could be a sign of spyware running in the background and sending information back to its server.