Trying to remove malware? I'll walk you through the steps and options, from simple to hard, including the only approach that's guaranteed to work.
One question that shows up almost every day in the Ask Leo! inbox is how to remove malware.
The scenarios may be different, but the problem is the same: a machine has been infected with spyware, a virus, or some other form of malware and that machine’s owner is having a tough time getting rid of it.
And it often happens with anti-malware software installed that “should” have taken care of it before it got to this stage.
Hopefully, that’ll never be you. If it is, let’s review the steps that I recommend for removing malware and reducing the chances that it’ll happen again.
A word about prevention
If there’s only one thing that I would have you take away from this article, it would be this:
Prevention is much less painful than the cure.
As we’ll see in a moment, the steps that may be required to remove malware can be painful and time consuming. While it sometimes might seem like work, keeping your machine and anti-malware software up-to-date, following internet “common sense,” and knowing how to stay safe on the internet is much, much easier in comparison.
So, let’s look at what to do when prevention has failed.
My strong recommendation is that you start by taking a complete image backup of your system.
Why would you want to backup a system that you know is infected with malware?
Because this backup is an “it-can’t-get-any-worse-than-this” fallback. Some of the techniques that we might use to remove malware can actually break things and make the situation worse instead of better. With this backup at the ready, you can always restore and start over with nothing lost.
Restore a prior backup
If you’ve been taking regular backups, this is often the most expedient step and can save a lot of time and energy.
Simply restore your machine completely from the most recent full system backup, plus any incremental backups, taken before the infection occurred. You can then carefully restore any late-changing data from the backup you took.
And, except for learning from the experience, you’d be done.
Unfortunately, most people don’t have this option available to them. Most people don’t begin backing up until after they’ve experienced data loss or a severe malware infection. One of the lessons they learn is that a recent backup is something that can save them from almost any problem – including malware.
Update the anti-malware database
If you have anti-malware software installed, make sure that it’s up-to-date. I’m talking about more than just the software itself, but the database of malware definitions.
Almost all anti-malware tools use databases of malware definitions, which needs to be updated regularly. New malware is constantly appearing, and as a result, that database of definitions needs to updated often – at least daily.
Many programs will do this automatically, but if for some reason they do not, then the programs will not “know” about newer malware. Make sure that the database is up-to-date so that yours does.
Perform a full scan
Quite often, anti-malware tools will regularly perform a “quick” or fast scan. That’s typically quite sufficient for day-to-day operations.
But not today.
Fire up your anti-malware tools and run a full/advanced/complete scan of your entire system drive – typically the C: drive. If you have a single tool, that might be one run; if you use multiple tools, such as separate anti-virus and anti-spyware tools, then run a full scan with each. This may take some time, but let the tools do their job.
This also covers if your anti-malware tools automated scans have stopped for some reason. If this full scan discovers something, it might be worth checking to make sure that the security software is properly configured to scan automatically as well.
Try another anti-malware tool
No anti-malware tool catches all malware.
I’ll say it again: there is no single tool that will catch every single piece of malware out there. None. Some are better than others, some catch more than others, but none of them catch everything.
So as you might expect, trying additional reputable tools is a reasonable approach.
I recommend the free version of Malwarebytes’ Anti-Malware as the first tool to use. It has a reputation for removing some nasties that other tools apparently miss. Once again, run a full scan.
Regardless of which tool you select, I have to stress: stick with reputable tools. When a machine is infected, most people tend to panic and download just about anything that claims to be an anti-malware tool. Don’t do that. There are many less-than-reputable individuals out there ready to take advantage of your panic.
Do some research before downloading anything or you may well just make the problem worse instead of better.
Research specific removal instructions
If your anti-malware software tells you the name of the specific malware you’re dealing with, that’s good information even if it can’t remove it.
Search for that malware and you’re likely to find specific removal instructions at one or more of the major anti-malware vendor sites. These instructions can often be somewhat technical and intimidating, so take your time to follow them precisely or get a techie friend to help.
They’ll also often come with recommendations that indicate that the vendor’s software will remove the malware – for a price. As long as it’s an option (in other words, the manual removal instructions are provided), then it may be a viable alternative if the company is one you trust. On the other hand, if all you’re presented with is a promise and a price, I’d move on.
Some sites offer free tools that you can download to remove specific malware. Once again, use caution. When the tools are from reputable sources, they’re a quick way to avoid some hassle. When the tools are really just more malware in disguise, they’ll only make your problems worse.
If you download anything to help address the problem, make sure that wherever it is comes from, it’s an organization that you know and trust.
This is the only sure-fire way to remove any virus. 100%. Guaranteed.
In fact, it’s the only way to know that you’ve removed a virus. Once infected, none of the steps above, aside from restoring to a backup taken before the infection, are guaranteed to remove the malware, even if they report that things are clean. Once infected, all bets are off. An infection could fool anti-malware software into thinking that everything is fine even when it’s not.
There’s just no way to know.
The only way to be absolutely positive that you’ve removed any and all viruses is:
- Back up: If you haven’t already, back up the entire system. You’ll use this to restore your data after we’re done.
- Reformat: Reformatting erases the entire hard disk of everything: the operating system, your programs, your data, and most important of all, any and all viruses and malware. This may be part of the next step as most Windows setup programs offer to reformat the target hard drive before installing Windows.
- Reinstall: Yes, reinstall everything from scratch. Reinstall the operating system from your original installation media. (Or restore the system to an image backup you took when you got the machine to preserve the “factory original” state.) Reinstall applications from their original media or saved downloads.
- Update: Update everything in particular making sure to bring Windows as completely up-to-date as possible for the most current protections against all known and patched vulnerabilities. Applications and particularly your anti-malware tools should be updated as well.
- Restore: Restore your data by carefully copying it back from the backups you created when we started. By “carefully,” I mean taking care to only copy what you need, so as not to copy back the malware.
- Learn: Take stock of how this happened, what you might have done to get infected in the first place, and what might have helped you recover more efficiently. Consider instituting a frequent system backup.
It’s not your fault (but it is your responsibility)
By now, I hope you can see why prevention is so much less painful than the cure.
Taking a few extra steps to keep things up-to-date, avoiding those cute virus-laden downloads and attachments, and just generally learning how to stay safe is much easier than the recovery process that I’ve just outlined.
And having backups can make the recovery process as close to painless as possible if you do get infected.
Yes, it’s not your fault, but it is your responsibility to do the basics to stay safe when you use your computer
In an ideal world, we’d never have to worry about malware or the “bad guys” trying to fool us into doing things we really shouldn’t. But you already know that this isn’t an ideal world; software isn’t perfect and never will be. There will always be someone out to scam the vulnerable.
Even though it’s not your fault, you still need to be the one to get educated and take the steps needed to stay safe.
Right or wrong, it’s just a practical reality.