I found an unwanted application on my personal laptop after installing a Nintendo emulator. My antivirus does not detect it, and uninstalling it only removes it temporarily—the application eventually returns. I also found and deleted a scheduled task that seemed to be reinstalling it, but it came back several days later. What steps can I take to identify its persistence mechanism and remove it safely?
4 Answers
If the installer came from an unofficial source, assume the system may be compromised. Back up only personal documents—not programs or unknown executables—then scan the backup. For the most reliable cleanup, reset or reinstall Windows from official installation media, delete the existing system partitions during setup, install updates, and change important passwords afterward.
First, identify the exact application name and where its files are located. Check Installed Apps, Task Manager, the Startup tab, Task Scheduler, and common startup folders. Also look for unfamiliar services or browser extensions. Without the program name, download source, and the way you know it returned, it is difficult to tell whether this is malware or a legitimate emulator component.
It is on my personal computer and appeared after I installed a Nintendo emulator. I am not sure which extra program caused it, but I will check those locations.
Run a second-opinion scan rather than relying only on your usual antivirus. Malwarebytes is one option, and an offline scan from Windows Security can check for software that hides while Windows is running. Disconnecting from the internet during cleanup may also prevent the program from downloading additional files.
Do not delete random files or scheduled tasks until you know what created them. Write down the exact name, file path, publisher, and startup trigger, then search those details using reputable security resources. If the application is still active, upload a suspicious file to a reputable multi-engine scanner only if doing so does not expose personal information.

I was confused by the suggestion to reinstall, since I meant that the unwanted program keeps reinstalling itself. I understand now that a clean Windows reinstall is different: it removes the existing system and should eliminate the persistence mechanism.