Keeping your computer clean and free from malware is important, and many companies out there make great products to help you do just that. But there are also a lot of people trying to take advantage of you, and they bank on the fact that you aren't paying attention. They'll offer features that sound important, but really don't do anything at all.

Sometimes the apps that you'll get suckered into downloading are system-cleaners that promise to clean up your computer and make it run faster. Sometimes they're "antivirus" apps that pretend to find malware so you'll buy the premium version of the app, or even download malware onto your computer. Here are a few tips for identifying these apps before they make it onto your computer.

Fake System-Cleaning Apps

MacKeeper is a program that professes to keep your computer clean and running quickly, but history has shown that it does anything but. Not only has it had multiple security vulnerabilities, but it's been shown to slow down computers, and tell you that you need to buy the premium version to get rid of all sorts of problems on your Mac. It's just not a good application. But how were you supposed to know that? It looked fine when you saw the website, right? Here are a few warning signs.

Take a look at this list of features:

mackeeper-too-short

But are there really three points here? Choose which apps open on startup, never miss updates on apps you use frequently, and use MacKeeper to do them both - it's really only two points, and not three (you'll see why bad writing can be a warning sign in a moment).

Second, you can already choose which items open at startup using the Login Items in your System Preferences. It's already built into OS X:

os-x-login-items

And the same is true with updating your apps. If you get your apps from the Mac App Store, you'll get notifications every once in a while saying that you need to run updates (though some other app stores do offer more convenient updates). Even if you didn't get an app from the App Store, it's pretty likely that it will tell you when it needs an update.

app-store-updates

"But I didn't know that I could do those things right from my Mac," you might say. And that's where the difficulty lies. You need to get familiar with what you can do with your computer, or unscrupulous marketers like those at MacKeeper can sell you what you already have for free. And unscrupulous marketing is often an indication of unscrupulous developing, which you don't want any part of.

Let's take a look at another part of the MacKeeper page:

mackeeper-safe-browsing

Let's think about the sentence "The Internet is the most vulnerable place for Mac security" for a second. Isn't it the only place where your Mac is vulnerable? Unless you're worried about someone introducing malware to your Mac via a USB drive -- which is exceedingly unlikely -- the Internet is your only concern. A sentence like this is only put on the website to scare you into thinking you need this app. Your antivirus provider shouldn't be trying to scare you, they should be trying to reassure you.

Which brings me to a related point: the antivirus app on your computer should focus solely on protecting you from malware. It shouldn't use GPS tracking to locate your laptop if it's stolen, it shouldn't be scanning for duplicate files, it shouldn't have an advanced search function built in; effective programs focus on one or two things. That's a big warning sign from apps like MacKeeper that something is amiss. If a program works well, it's going to work well doing one thing, or maybe a couple. But not 16, as MacKeeper claims.

Finally, let's take a look at those 16 different apps.

mackeeper-16-in-1

First of all, there's at least $100 worth of things listed that you get for free already, like backup, update tracking, file finding, and data encryption. But that's not what really stands out here. If someone claims that their software is worth over $500, but that you can get it for 97% off, you should be worried. No one gives away that much stuff for free. Yes, sometimes there's a sale or a bundle where you can get a huge savings, but this is the standard price, and that should set off a warning bell.

Another thing that should set off a warning bell is that their "Internet Security" is valued at $80, which is quite a bit more than a large number of antivirus companies with world-class reputations. Norton, one of the biggest and best options out there, is only $60 per year after a $40 intro year. Kaspersky is $30 for the first year and then $40 after that. If you're paying $80 for a no-name antivirus, you're getting ripped off. Mac antivirus programs just don't cost that much.

Between trying to sell you things you already have, some questionable marketing practices, and a very clear, very large overestimation of the value of their product, a description like this should make you nervous.

Fake Antivirus Apps

Rogue antivirus apps, as they're called, can be even more insidious than apps like MacKeeper. If you get one that's bad enough, it could be downloading malware to your computer instead of trying to help you get rid of it! We've shown you how to recognize fake virus warnings, and that's a good first step in keeping your computer free of this menace. But you should learn to recognize the signs you can look for on a website, too.

Here's the Antivirus Security 360º website:

antivirus-security-360

First, let's talk about the obvious -- the poor formatting. "Mobile" shouldn't be capitalized, "cloud" should be, and "Firewall" shouldn't be. "Scan detect and clean virus, spyware + Firewall" is a poorly constructed and punctuated sentence. "Automated database updated" doesn't even mean anything. All of these should tip you off to the fact that this page was not proofread before it was posted. That doesn't mean anything bad in itself, but if a company has put a lot of time and money into making a great product, they're likely to make sure they've put some time and money into building a decent website. This company obviously hasn't.

Here's another paragraph from the homepage:

Free Antirus Software as AVG have been tested by many affiliate and content provider over the internet. You will find hundreds of videos on Youtube describing antivirus installation and functionnalities. Be carefull that some of thoses Antivirus Videos leads to fake antivirus provider, we found here a trustable testing review. For for best security, always download AVG Free Antivirus from AVG.com … Have a safety Surf !-

100 millions users worldwdide and now quote on the market, the same week as facebook. AVG Antivirus is widly search for his free edition, it is indeed a teaser to upgrade to the internet security or adding the anti spyware.Installing or uninstalling

Sentences like "Have a safety Surf !-" should have you hitting the Back button fast. Also, the text is obviously partially copied from the AVG website. I decided to check out their Contact page to see if there were any warning signs there, and this is what I saw:

antivirus-360-contact

Turns out Antivirus Security 360º is run by a company called "My Corner Bar." Doesn't sound like a developer of effective antivirus software, does it?

With antivirus software, the warnings aren't always going to be this obvious. Most fake antivirus apps are downloaded via Trojans or bundled with other software, meaning you probably won't be perusing their website like this. However, some of the same warning signs could present themselves in alerts, pop-ups, or other kinds of communications. They may even show the name of a program that isn't on your computer, which is a big warning sign.

To protect yourself from most of them, you'll need to use basic cybersecurity principles -- don't download something if you didn't go out looking for it, only download things from the manufacturer's website or an app store (instead of a download site like Download.com or Softonic), and pay attention to what installation dialogs are telling you.

Don't Be Fooled

Most of the warning signs for fake system-cleaning apps like MacKeeper are fairly obvious if you know what you're looking for and what your computer does. If you're not sure which functionalities you have built into your computer already, be sure to read the proper section to find out more! We have sections for Mac, Windows, and Linux, and each will help you learn the kinds of things you can expect from your software.

When it comes to bad antivirus apps, your best bet is a good antivirus app to detect if something has been downloaded when it shouldn't have been. Beyond that, watch out for sites that have egregious errors, those that have been copied from other legitimate sites, and those that are trying to scare you into downloading their app.

Have you downloaded any apps like this? Which ones? Did they adversely affect your computer? Did you have trouble getting rid of them? Share your experiences in the comments below!