I downloaded a file from someone online after disabling Windows Defender. The next day, my GPU started jumping to 100% utilization whenever the computer sat idle for 15–20 minutes. Moving the mouse briefly makes a blank window appear and disappear. Task Manager shows a suspicious process called "Diniizz jpeg" running from AppDataRoamingMicrosoft. I reinstalled Windows from a USB drive and deleted the partitions, but the behavior still happens. When the malware starts after the computer sits idle, several files also seem to disappear from that folder after I move the mouse. What should I do, and how can I tell whether the reinstall was actually clean?
4 Answers
Create fresh Windows installation media using another known-clean computer. Do not reuse the USB drive that may have been connected to the infected machine. Boot from the new installer, remove every partition on the target drive, install Windows, and immediately apply all updates before restoring files or installing programs.
The symptoms sound consistent with a crypto-mining malware, especially since it uses the GPU only when the computer is idle. Disconnect the computer from the internet, avoid logging into accounts from it, and change your passwords using a different, trusted device. Then back up only personal documents you know are safe and completely wipe the system drive before reinstalling Windows.
If a genuinely clean installation still shows the same process, check what you are restoring or reinstalling. A backed-up installer, cracked application, browser extension, scheduled task, or copied executable could simply be bringing the malware back. Scan backups separately and reinstall software only from official sources.
Do not assume the files are harmless just because they disappear when you move the mouse. Malware often hides or removes its own components when it detects user activity. If the machine contains important accounts or sensitive data, treat it as compromised and perform password changes, session sign-outs, and security checks from a separate clean device.
A factory reset from inside Windows may leave things behind, so the reinstall should be started from installation media and the existing partitions should be deleted during setup.