If you install a program and your computer runs much slower, you should suspect malware is at work, especially if the promised action fails to materialize. Sure, if you install a huge hunk of software, you can expect your computer to drop the pace a bit. But if you install a small program and your computer crawls like molasses, something is up.
6. Your antimalware tools have been disabled
Here's a huge warning sign: Your antimalware tools or firewall no longer work. Unless you downloaded and installed another antimalware product or personal firewall, the ones you are currently running should still be active. But many malicious programs start by disabling your current protection.
7. Task Manager does not start
Along the same lines, if you try to start Task Manager and it doesn't load, you probably have malware to blame. I've also seen Task Manager pop up for a second, then disappear. It's the same situation.
8. You can't uninstall the program
A legitimate program is required to include an uninstall option, but malware programs don't like to be uninstalled. If the newly downloaded program doesn't uninstall, look out. If it includes an option to uninstall, but doesn't carry out the action, look out. Yes, uninstall routines sometimes get hosed and fail -- but usually not right away.
9. A funky end-user license agreement
Most people don't read the end-user license agreement (EULA) before they install a program. I do -- and I've seen malicious acts spelled out in English. I've seen one EULA that claimed after the program was installed, my computer and data was its property and it reserved the right to disable any action I took to uninstall the program. That EULA certainly wouldn't hold up in court, but at least it warned me.
What should you do?
When in doubt, chicken out and don't install. Close the browser if you have to. If it's truly legitimate software that you need to access a website, go directly to the vendor's website to download. For example, if you absolutely need Adobe Acrobat, open a new browser window, surf to adobe.com, and install it from there.
What if it's too late?
Fire up your antivirus scanner to see if it detects any abnormal activity. Better yet, if you have a Windows computer, use Microsoft's free Process Explorer utility that runs all active executables against up to 57 antivirus engines. See my prior article about this or watch my video. You can't beat its accuracy of this method for detecting malware.
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