A Command Prompt window appeared for about a millisecond after I visited some suspicious websites yesterday. When I started my PC today, I also saw a Windows notification claiming that 360 Security's files were corrupted and needed to be reinstalled. I didn't knowingly download or run anything or grant permission. Could this indicate malware, and what should I do to check and clean the computer?
2 Answers
Visiting a questionable site alone usually isn’t enough to infect a current Windows system, especially if you didn’t download or run anything or approve a prompt. Still, treat the behavior seriously: avoid using that security program’s pop-up as proof of anything, update Windows, and run a full scan with the built-in Microsoft Defender. Also review recently installed programs and browser extensions, and remove anything unfamiliar.
Start with Microsoft Defender’s full scan, and consider running its offline scan if you’re especially concerned. Keep the security definitions updated first. A brief Command Prompt flash can also come from a scheduled task, updater, or startup program, so it isn’t automatically proof of a virus. If scans detect something, follow the cleanup instructions and change important passwords from a separate, clean device.
I didn’t run any downloaded software or approve a prompt, but I’ll check my installed programs and run a full scan to be safe.