How can I tell if I have a malware infection?
Malware can reveal itself with many different aberrant behaviors. Here are a few telltale signs that you have malware on your system:
Your computer slows down. One of malware’s side effects is to reduce the speed of your operating system (OS), whether you’re navigating the Internet or just using your local applications, usage of your system’s resources appears abnormally high. You might even notice your computer’s fan whirring away at full speed—a good indicator that something is taking up system resources in the background. This tends to happen when your computer has been roped into a botnet; i.e. a network of enslaved computers used to perform DDoS attacks, blast out spam, or mine cryptocurrency.
Your screen is inundated with annoying ads. Unexpected pop-up ads are a typical sign of a malware infection. They’re especially associated with a form of malware known as adware. What’s more, pop-ups usually come packaged with other hidden malware threats. So if you see something akin to “CONGRATULATIONS, You’ve won a free psychic reading!” in a pop-up, don’t click on it. Whatever free prize the ad promises, it will cost you plenty.
Your system crashes. This can come as a freeze or a BSOD (Blue Screen of Death), the latter occurs on Windows systems after encountering a fatal error.
You notice a mysterious loss of disk space. This could be due to a bloated malware squatter, hiding in your hard drive aka bundleware.
There’s a weird increase in your system’s Internet activity. Take Trojans for example. Once a Trojan lands on a target computer, the next thing it does is reach out to the attacker’s command and control server (C&C) to download a secondary infection, often ransomware. This could explain the spike in Internet activity. The same goes for botnets, spyware, and any other threat that requires back and forth communication with the C&C servers.
Your browser settings change. If you notice your homepage changed or you have new toolbars, extensions, or plugins installed, then you might have some sort of malware infection. Causes vary, but this usually means you clicked on that “congratulations” pop-up, which downloaded some unwanted software.
Your antivirus product stops working and you cannot turn it back on, leaving you unprotected against the sneaky malware that disabled it.
You lose access to your files or your entire computer. This is symptomatic of a ransomware infection. The hackers announce themselves by leaving a ransom note on your desktop or changing your desktop wallpaper itself in to a ransom note (see GandCrab). In the note, the perpetrators typically inform you that your data has been encrypted and demand a ransom payment in exchange for decrypting your files.
Even if everything seems to be working just fine on your system, don’t get complacent, because no news isn’t necessarily good news. Powerful malware can hide deep in your computer, evading detection, and going about its dirty business without raising any red flags. While we’ve provided a quick malware spotter’s guide, it really takes the unfaltering eye of a good cybersecurity program to detect malware on your system (more on that later).
https://www.malwarebytes.com/malware