Modern viruses are quiet. They don't always crash your PC — they steal passwords, encrypt your files, or mine cryptocurrency in the background. Here are the seven red flags we tell every client in Pretoria to watch for.
1. Your PC suddenly feels sluggish
A sudden, unexplained slowdown — especially with the fan running loud when you're not doing anything — often means malware is using your CPU in the background.
2. Pop-ups appear even when your browser is closed
Legitimate websites don't push ads onto your desktop. If you're seeing adverts, warnings, or 'call this number' pop-ups outside your browser, you almost certainly have adware or a browser hijacker.
3. Your browser home page or search engine changed on its own
If Google is suddenly replaced with an unfamiliar search page, or your home page keeps resetting to something weird, malware has taken control of your browser settings.
4. Files are missing, renamed, or won't open
This is one of the most serious signs — it usually means ransomware. Don't restart, don't pay anything, and disconnect from the internet immediately. Call a professional.
5. Your antivirus is disabled and won't turn back on
Serious malware will actively disable Windows Defender or your antivirus to protect itself. If security tools keep switching off, that's a bright red flag.
6. Friends receive strange messages from you
If people tell you they got weird WhatsApp, email, or Facebook messages 'from you' that you didn't send, an account or your device has been compromised.
7. Unfamiliar programs or browser extensions appear
Check your installed apps and browser extensions regularly. Anything you don't recognise — especially 'PC optimisers' or 'coupon helpers' — should be removed.
What to do next
1. Disconnect from the internet to stop data being sent out.
2. Don't type any passwords or open banking sites.
3. Run a full scan with a reputable tool like Malwarebytes or AVG.
4. If files are encrypted or the scan won't complete, bring the machine to a professional. Trying to 'fix' ransomware alone often destroys the recovery chances.