Ask Leo! #708 – How Do I Know if My Machine is Free of Malware?

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Featured: Knowing the unknowable.

Also this week: Redistributables, redistributables, redistributables! And the sad state of router security.

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How Do I Know if My Machine is Free of Malware?


How do I find out or know that my computer is free of keyloggers? Would Windows Defender or MalwareBytes find them if there are any, or do you have a referenced article on the topic where I can read about it? Understand that this is the biggest security concern I have about my computer nowadays.

How do you know your computer is free of keyloggers? You don't.

It's not the answer most people want to hear, but it's the true bottom line.

There are a few reasons for it, which I'll discuss, as well as what you and I need to do in the face of this rather grim reality.

A quick note about keyloggers

Be it “keyloggers” or the ever-popular “ransomware”, some terms seem to get people's attention more than others.

We need to be clear about something: there's nothing special about keyloggers, and there's nothing special about ransomware. The names describe what they do, not what they are. What they are is very simple: they're just forms of malware.

What they do once they arrive might be interesting or severe, but the fact that they are malware warrants our attention. Like any form of malware, the most important thing to do is to prevent them from getting on your machine. The second most important? Detection and removal.

But this applies to all malware.

Proving a negative

There's no way to absolutely know or prove that your machine doesn't have malware.

Looking for malware and not finding it isn't enough — there's no guarantee your anti-malware tools know all the malware to look for, or all the ways that malware could hide.

No anti-malware tool is guaranteed to catch every possible malware. None. By definition, the creation of malware is always ahead of its detection. Even the very best anti-malware tools are always playing catch-up.

If you run a zillion different anti-malware tools and they all come up empty-handed, this doesn't prove you have no malware. All it says is that it's  highly unlikely…

… which, pragmatically, is the best we can hope for.

Staying safe, without proof

The best you and I can do is to stack the deck in our favor.

Make it difficult for malware to arrive. That means not installing untrusted software, not opening random attachments, making sure your firewall is doing its job, not falling for phishing attempts, running good security software, and more.

Make it likely that any malware that makes it through will be caught. That means making sure you're running up-to-date security software and that it's scanning appropriately.

Make it possible to recover quickly with minimal impact if something isn't caught immediately. That means backing up regularly.

Ultimately, it all boils down to the set of rules and admonitions folks in my position have been preaching for years…

… rules and admonitions I've laid out in what I consider to be my single most important article: Internet Safety: 7 Steps to Keeping Your Computer Safe on the Internet.

Even getting out of bed is risky

I wish I could offer you a 100% guarantee — a way you can be completely certain your machine is free of malware and all is well.

I can't. Just like we can't guarantee that we won't get hit by a bus or fall down the stairs.

All we can really do is stack the deck in favor of our safety. Look both ways before crossing, hold the handrail, and stay safe online.

There are no guarantees. But, while you should never reduce your vigilance, you can absolutely reduce your concern and carry on using your technology in all the wonderful ways it was intended.

Related Links & Comments: How Do I Know if My Machine is Free of Malware?

The Ask Leo! Guide To Staying Safe On The Internet ' Expanded Edition

Do I Need These Microsoft Visual C++ Redistributables?

I'm wondering if I need all of these Microsoft programs on here, like Microsoft Visual C++ 2005 redistributable or Microsoft Visual C++ 2008 redistributable. It's taking up space on my hard drive and I'm wondering if those programs are really necessary.

Time for my most common, yet most annoying answer:

it depends.

I'll describe what the Visual C++ redistributables are all about, and why the safest thing to do is probably to leave them alone.

Continue Reading: Do I Need These Microsoft Visual C++ Redistributables?

What Should I Do About the VPNFilter Router Exploit?

Malware known as VPNFilter is infecting routers world-wide. Depending on what you read, hundreds of thousands, if not millions, of routers are impacted.

Not all routers are affected, and what steps to take will vary depending on what router you have. The good news appears to be that if you've already followed best router safety practices and changed the admin password, your router may well be immune.

The problem? There's no way to confirm that your router is or is not impacted. What you need to do, if anything, varies depending on the router you have.

Continue Reading: What Should I Do About the VPNFilter Router Exploit?

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Posted: June 12, 2018 in: 2018
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