Can I Be Sure My Machine Is Malware Free?

I’m running various virus and malware checkers, but my computer seems more sluggish all the time. A guest borrowed my PC and may have browsed some questionable sites. Any suggestions? I’m very nervous about logging into my bank online. A keystroke logger could grab my data.

As it turns out, there’s actually no way to prove that you don’t have malware on your machine. From a logical perspective, you can’t prove a negative.

You didn’t say what tools you’re running, so it’s hard for me to judge the answer to your question. If you’re concerned, let’s look at what you can do.

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Run a good anti-malware tool, like Microsoft Security Essentials. Make sure that both the program and the database are up-to-date so they can protect you from the latest threats.

Run Malwarebytes anti-malware. That’s a free tool from that’s very good at finding malware.

Consider running Windows Defender Offline if you don’t already run Microsoft Security Essentials. When you boot this program from a CD, software on your machine – in particular any malware that might be there – will not inhibit the ability of Windows Defender Offline to detect things. It’s also just a good idea to have a different program.

Of course, back up twice: before you do all of this and then after you think you’re clean.

VirusSluggish means malware?

Many people jump to the conclusion that a slow computer means malware. It could be, but other issues cause sluggishness as well.

I have a couple of articles – “Why is my machine slowing down?” and “How do I tell what program is slowing down my machine?” – which explain what’s happening with a pokey computer and what you can do about it.

It may be malware, but you definitely want to check all avenues before making the decision.


3 comments on “Can I Be Sure My Machine Is Malware Free?”

  1. My computer of choice is an old Intel Pentium 4 with Windows XP , an Asus 1yo $50 video card & 2GB of ram. It blasts along at an impressive pace.
    Keeping it clean is the key …I do a complete reinstall about every 2 years brings back that new computer feel.

  2. I think it’s a good thing we think of malware first when our machine acts sluggish. It means that it’s at the front of our mind and we’re more likely to do an extra scan or make sure our anti-malware software is up to date. Ultimately that will keep us safer.

  3. I normally have Task manager and a packet sniffer running. Often too.
    So if things slow down it’s easy to find the cause.
    Sometimes it’s just a program not behaving as it should, while it’s running normal on another computer with the same operating system. That’s just bad luck.
    I’ve one computer freezing all of the time on Internet Explorer, decided not to use it anymore.
    Sometimes on Window XYZ it’s related to a updater.
    Never seen a slow down because of some malware, except a long time ago when I found 300+ viruses and the like on the system.
    But then I can’t remember when I encountered the last “infection”.

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