Has your computer been acting strangely lately? Is it running slower than usual, displaying odd ads, or behaving erratically? These could be signs of a malware infection. While a blatant ransom note is a clear indicator of a hack, other symptoms are more subtle. This article outlines five common signs of a compromised computer and provides actionable steps to investigate and resolve the issue.
Is your computer running slower than usual, displaying odd ads, or behaving erratically? These could be signs that your computer has been hacked. While a blatant ransom note is a clear indicator, other symptoms can be more subtle. Here’s how to detect and address a potential malware infection:
1. Sluggish Performance and High CPU Usage
Symptom: Your system runs noticeably slower. Programs take ages to load, and your CPU utilization consistently hovers near 100%.
Harmless Causes: High CPU usage can result from legitimate, resource-intensive tasks like video compression or complex image processing. On older machines, even HD video playback can strain the CPU. A known Windows 10 bug can also falsely report 100% CPU usage. Occasionally, software glitches can cause a program to consume excessive CPU resources.
Dangerous Causes: Ransomware is a serious threat. It encrypts your files and demands payment for decryption. This process can take hours, resulting in sustained high CPU usage. Cryptojackers (mining malware) are another culprit. They hijack your CPU to mine cryptocurrency, often Monero.
Investigation: Open Task Manager (CTRL+SHIFT+ESC) and click “More Details.” Sort processes by CPU usage to identify the resource hog. For a more detailed view, use Process Explorer. A scan with a second antivirus program, like Norton’s Power Eraser, is also recommended.
Norton Power Eraser can help identify and remove stubborn malware.
Solution: Research the problematic process name online, adding “100% CPU” to your search. Solutions often involve software updates or malware removal. Be wary of shareware cleaning tools; free antivirus software usually suffices.
Browser Issues: High CPU usage within the browser might indicate a cryptojacker. Closing the affected website or tab often resolves this. If the issue persists, uninstall suspicious browser extensions.
2. Excessive Hard Drive Activity
Symptom: Your hard drive LED blinks constantly, and if you have an HDD, you might hear increased drive noise.
Harmless Causes: Legitimate processes like Windows Indexing Service or antivirus scans can cause high hard drive activity.
Dangerous Causes: Ransomware encrypting your files is a primary concern. Less common, but still dangerous, is spyware actively searching through your data.
An external hard drive connected to a laptop.
Investigation: Use Resource Monitor (Windows-R, type resmon) to identify the process causing the activity. Switch to the “Disk” tab and sort by “Total.” Ransomware exhibits similar read and write activity, while legitimate processes usually show higher read activity.
Solution: Research the identified process online. End the process in Task Manager (right-click, “End Process”). Upload suspicious files to VirusTotal for analysis.
3. Interrupted Internet Connectivity
Symptom: Slow browsing, buffering videos, and sluggish network file transfers.
Harmless Causes: Wi-Fi issues, a slow internet connection, or large uploads/downloads can cause network slowdowns.
Dangerous Cause: Malware could be uploading stolen data from your computer.
Investigation: Use Resource Monitor’s “Network” tab to identify processes with high network activity. Test your Wi-Fi by connecting directly to your router with an Ethernet cable. Check your internet speed. Use “Down for Everyone or Just Me” to check website availability.
Checking internet speed can help diagnose connectivity issues.
Solution: Contact your internet provider if your connection is slow. Upload suspicious programs to VirusTotal.
4. Unwanted Advertisements
Symptom: Pop-up ads appear on your desktop or browser, exceeding the usual amount.
Harmless Cause: Websites with excessive advertising can sometimes trigger pop-ups.
Dangerous Cause: Adware can install itself on your computer and display persistent ads, sometimes disguised as virus warnings promoting paid software.
Investigation: Scan your system with an anti-adware program like Adwcleaner. Test your browser without extensions by starting it in safe mode or incognito mode.
Solution: Adwcleaner can usually remove adware from your browser.
5. Unusual Android Behavior
Symptom: Unexpected pop-up ads on your Android device or overheating without running apps.
Harmless Cause: Ad-supported apps can display ads.
Dangerous Cause: Adware or malware could be stealing data, including banking information.
Investigation: Use an antivirus app like Sophos Intercept X.
Solution: Sophos Intercept X can usually remove detected malware.
