Antivirus software catches a lot, but modern malware is designed specifically to evade it. Here are five signs that something is wrong even when your security software shows a clean bill of health.
1. Your browser home page or default search changed
Browser hijackers slip in bundled with free software. They're not dangerous on their own, but they're a sign that something was installed without your full knowledge — and they may have brought friends.
2. Your computer runs hot when it should be idle
Cryptomining malware uses your processor to mine cryptocurrency in the background. If your fan is running loudly when you're not doing anything demanding, check Task Manager for processes using unexpected CPU.
3. Outbound network traffic you don't recognize
Use your router's traffic logs or a tool like Wireshark to look for unexpected outbound connections. Data exfiltration malware is quiet, but it has to phone home eventually.
4. Programs launching at startup that you didn't install
Open Task Manager, go to the Startup tab, and look for anything unfamiliar. Legitimate software names strange startup entries sometimes, but anything truly unrecognized is worth investigating.
5. Sudden password failures
If accounts you haven't touched are suddenly locked or showing login attempts from unexpected locations, assume a credential harvester was involved. Change passwords and enable 2FA immediately.