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STOPzilla started life as a simple web-browser pop-up blocker for Internet Explorer (back in 2001), but has since morphed into a suite of Windows security and optimisation products (plus and Android app) that taken together provide a very comprehensive and robust solution for protecting Windows PC’s and getting the best out of them.

Visit StopZilla »

Given the wealth of well-respected free Windows software aimed at covering similar ground, we admit to entering this review somewhat leery of what a commercial product could add to field. However, as we shall see, the STOPzilla software ended up impressing us with the all-inclusiveness of its tools, which when combined with great (live) customer support, makes its products particularly good for businesses that need robust commercial solutions. It should also be noted that while free software is widely available fo personal use, this is not true for businesses, and in these terms the pricing for STOPzilla’s products is competitive.

We should also note that STOPzilla is proud of being based in the USA and of developing its software in the USA, which may worry the more NSA-paranoid. It is also not open source (but then very few anti-virus programs are).

The suite

The full STOPzilla suite consists of four stand-alone security products, all of which come with some form of free trial:


Once the trial period/conditions are up, the software costs the following:

  • STOPzilla 7.0 – $39.95 for 1PC / 1 year, going up to $89.95 5 PCs / 1 year. US based customers can opt to pay for an installation service (starting at $20 for 1 PC) where a STOPzilla technician will come round in person and set everything up. Available for Windows Vista+ only
  • STOPzilla AntiMalware 6.0 – $19.95 for 1 PC / year, going up to $39.95 for 3 PCs / year. The Installation Service (US only) is $20 for up to 3 PCs. Windows Vista+ only
  • STOPzilla Mobile – $9.95 / year. Android 2.01 only
  • STOPzilla Optimizer 3.0 – $19.95 for 1 PC, going up to $79.95 for 5 PCs (full purchase, not a yearly subscription). In addition to the fixed trial there is a 30 day money back guarantee, and, and a US installation service starts at $20 per PC.

For the record, this reviewer uses the following (recommended) free security products on a daily basis, and will therefore use them as the basis for comparison in this review:

Visit StopZilla »

 STOPzilla AntiVirus

The ‘core product’ in this suite of security utilities is of course STOPzilla AntiVirus 7, a comprehensive anti-virus package with a feature-set to rival the ‘big boys’ such as Norton. It is important to note that this package includes STOPzilla’s AntiMalware software, and so the two packages cannot therefore be installed together.


The interface is smart looking, cleanly laid out, and is easy to navigate and understand

AntiVirus email protection

Email protection is included, which is great for users of dedicated email clients. Webmail services (such as Gmail) are not supported, but such services usually have their own protections anyway

AntiVirus email protection

STOPzilla AntiVirus performs real-time virus detection, and it is possible to delve into the details of which locations are protected (it is probably best to just leave this alone unless you know what you are doing!)

AntiVirus enforcers

Additional tweaks can be made through the Application Settings. Mouse-over popups explain what each setting does

How effective is it?

This is of course, the $64 million question when it comes to comes to anti-virus software…

Disclaimer: Testing the effectiveness of anti-virus and anti-malware software is not easy (at all), and is therefore the province of anti-malware professionals (which we are not), who can safely and ethically obtain viruses with which they can test security products within safe and secure environments.

Unfortunately, we can find very few online reviews for STOPZilla products that include robust testing results (the highly respected independent IT security outfit AV Test, for example, has not included STOPZILLA in any of its group tests.) Back in 2007 PC Magazine reviewed STOPzilla 5.0, giving it a rather unimpressive score of 2.5 out of 5, but as this is review is now almost 8 years old, and as STOPzilla 7.0 is likely much more advanced than STOPzilla 5.0, judging the product by this review seems very unfair.

What we have done is test STOPzilla using the Anti-Malware Testfile created by the European Institute for Computer Antivirus Research (EICAR) and Computer Antivirus Research Organization (CARO), to test the response of computer antivirus programs. An academic paper discussing malware simulation and the EICAR test file is available here (pdf).

This file (which is available in various compression formats designed to test anti-virus and anti-malware’s detection abilities) is not itself malware, but is designed to trigger a response from any good anti-virus and anti-malware software (Windows only).

The Testfile cannot measure how effective software is at detecting the often very subtle viruses that exist ‘in the wild,’ but does at least indicate a basic level of competence, and since the discontinuation of the suite of malware detection testing tools developed by Spy Car, it is the only such tool available to the public (that we are aware of at least).

Windows Defender immediately detected and blocked all versions of the Anti-Malware Testfile (although as we shall see below, while it blocked all versions of the Testfile from being opened, at least one Testfile nevertheless ended up residing on our PC.)

We also compared STOPzilla’s capabilities by performing a full scan using Windows Defender. This took 5 hours and 53 minutes to complete, and detected 2 malicious files – one of which was an EICAR test file that it had prevented from opening, but which had nevertheless found its way onto the system.

Then, without deleting the detected ‘malicious’ files, we ran a full scan using STOPzilla. This took a similar amount of time, but produced many more results. These results should be treated carefully, though, as some were verified ‘false positives’, and others pointed to ad-supported freeware that we had agreed to (‘greyware’). Removal of the identified files could in these situations cause legitimate software to stop functioning.

AntiVirus results

We are a little confused about why gpg4win is flagged up as containing malware. It was downloaded from the official website and has been hash-checked (although we have now deleted it just to be sure)

Unfortunately in this regard, STOPzilla does not link results to a database of malware descriptions (as, say, McCafee Antivirus does), so if you wish to understand them you will need to hunt around on the web.

It should be noted that almost all results (apart from successfully detecting the EICAR Testfile) were found not on our system drive, but on additional hard drives that contain old installations of Windows. This would suggest that Windows Defender only scans the system drive (which on our system is a fast SSD), while STOPzilla scanned all attached drives. This means that is in fact much faster than Defender.

Visit StopZilla »


We are quite impressed with the comprehensiveness of the results, and the overall speed with which they were performed. If treated carefully, STOPzilla uncovered issues that our standard anti-virus and anti-malware software failed to uncover, which is excellent.

We are slightly concerned that the casual user is likely to just hit the ‘Clean’ button, which could cause problems when using some legitimate programs. This, however, is likely to be less of a problem for most users than for this this reviewer using his personal computer, because as a security reporter and software reviewer, my PC is likely to contain more ‘greyware’ issues than is common.

STOPzilla AntiMalware

This product is designed  to compliment users’ existing anti-virus software, and will work alongside it (although as already discussed, not STOPzillla AntiVirus already includes this program’s functionality and is not compatible with it).

It is designed to find elements that are not strictly viruses or ‘malware’, but which most users would likely prefer not to have on their system (even if you downloaded the program yourself), including invasive adware and Potentially Unwanted Programs (PUPs).

Malware scan type

Different levels of scan are available

Malware settings

The settings allow for a fair degree of customization, and real-time protection is included. STOPzilla Malware successfully blocked the EICAR Testfile

MalWare first screen

Unsurprisingly, many results mimicked those found by the STOPzilla AntiVirus software (which includes AntiMalware scans). Note that thanks to auto-fixing as a result of interrupted scans following reboots required when testing the software, the total number of threats found was much higher than shown here. It should be noted that scans can take quite a while


As with AntiVirus, STOPzilla’s AntiMalware program seems very good at picking up nasty bits of software, although some care should be taken in determine what in fact requires removal. We ran this package alongside Windows Defender without any issue, so it does indeed make a nice compliment to any existing AV software.

STOPzilla Mobile

The STOPZILLA mobile app (available from the Play Store, where it is rated 3.8/5) offers the following features:

  • Anti-virus and anti-malware protection – install scanning, real-time scanning and on-demand scanning
  • Anti-theft protection – ability to locate, lock, wipe, audio alert, or message your device remotely
  • ‘In-The-Cloud scanning’ – protection against malicious websites, will warn you when visiting a website that contains phishing, fraud, malware, or simply isn’t trusted
  • Application audit – easily track each installed apps permissions (also indicates apps that have access to billable functions
  • Event viewer – logs notable events

Before first signing-in to the app you must agree to a scarily long License Agreement, but scanning through it the main thrust as far as users privacy is concerned can be summarized by the following quote,

The status information is collected by iS3 for the purpose of evaluating and improving iS3’s product performance and installation success rate. This information will not be correlated with any personally identifiable information.

… which does not seem too bad.

 Mobile file scan

The Malware Scanner took around three minute to scan our Nexus 7 (2013), while a similar scan using Malwarebytes took 6 minutes

Mobile audit

The Mobile Audit tool can handily filter by Privacy Control, or by apps that can cost you money

Mobile anti-theft

Anti-theft protection functions can be accessed by visiting using a web browser. Everything seems to work well (although device location only functioned once we had closed the VPN connection o our Nexus)


Coming in at just 814k in size (not including data), STOPzilla Mobile is an easy to use and very lightweight app (Malwarebytes is a 7.3MB). In terms of functionality it does not has nearly as many features as, say, Norton Security and Antivirus, but seems to do what it does well, and it is nice to have Anti-theft protection built into a single app (rather than using an additional app such Google’s own Android Device Manager.)

STOPzilla Optimizer

STOPzilla Optimizer scans the Windows Registry for errors, removes junk files, and optimizes (defrags) you hard drives. It also scans for updated drivers, compacts the registry, and removes unwanted history data from your PC.

Although useful for keeping your PC running lean and mean, programs such as this have a reputation for being overzealous at removing important system files, which can damage a Windows installation and even prevent Windows from running altogether.

Optimizer home

As with all STOPzilla products, Optimizer 3.0 is clearly laid out and a breeze to use

Optimizer registry results

The Registry Cleaner found 144 errors…

CCleaner registry scan

… whereas CCleaner found only 26. CCleaner is very well respected, which makes us worry a little about how many errors STOPzilla Optimizer found (i.e. whether it is being over-aggressive), but after hitting ‘Fix All Errors’ in STOPzilla, we did not encounter any system problems, although we find ourselves having to re-associate file types with programs and fix other minor nuisances.Interestingly, a rescan using CCleaner turned up exactly the same errors as it found earlier, so the two programs are obviously detecting entirely different problems

Optimizer system cleaner 1

You can tell the System Cleaner where to look…

Optimizer system cleaner 2

… and it does a good job of rooting out files (CCleaner found many more files, but by default it often cleans out stuff that you might rather it didn’t, such as browser caches. Much of this functionality is anyway performed by STOPzilla Optimizer using its Privacy Protector scan instead)

 Optimizer system defrag

We did not test the Disk Optimization feature because our system uses a Samsung SSD as its primary drive, which is managed by its own optimized software that we prefer not to mess with. We are sure that STOPzilla Disk Optimization works just fine, but will note that Windows include this feature built-in (this was known as Disk Defragmenter, but has been renamed Optimize Drives in Windows 8.) Although it is nice to have all PC optimization software in one place, this does make this StopZilla feature rather unnecessary

Optimizer system drivers

The driver scan is a great utility, and makes keeping up-to-date with the latest system drivers a doodle. STOPzilla will safely backup old drivers in case there is a problem and the changes need to be rolled-back


STOPzilla Optimizer is an easy-to-use and powerful tool for streamlining Windows. While far from we would consider essential, it yielded impressive results, and would benefit anyone who likes to keep a tight ship when it comes to Windows. We like it!

STOPzilla Customer service

Customer support is available via ‘Live Chat’, email or telephone. We sent an inquiry via ‘Live chat’ and were informed by email that we would receive a response with 24 hours (the chat was not very ‘live’!). In fact, two days later support had still not responded at all. The next day, however, an operative was available immediately, so we must have just been a little unlucky.


Our telephone support experience was much more positive. The team member who assisted us was friendly, knew what she was doing, and offered to remote-operate our PC to remedy any problems, which left us impressed (we are sure that Live Support would be similarly good had it been available when we requested it). Customers in the USA, Canada, UK, and Australia can contact STOPzilla using toll-free numbers.

A ‘Premium’ telephone support service is also available, where STOPzilla staff will remote-operate your PC in order to perform repairs, remove existing viruses, and perform other general PC-repair type services not related to STOPzilla products. Judging from our experience with the ‘regular’ phoneline support, this service is likely to be pretty good, although it does require ringing a US premium-rate number.

STOPzilla is accredited by the respected non-profit organization focused on advancing marketplace trust, the Better Business Bureau, which speaks well of its ‘commitment to make a good faith effort to resolve any consumer complaints,’ but this does not in any way endorse the effectiveness of its products.

Final thoughts

All of STOPzilla’s products look good, are easy to use, and impressed us with both their power and comprehensive range of tools. Despite boasting 9 million existing users worldwide, STOPzilla is not a well-known player in Windows security space, but this may perhaps change with this well thought out range of products.

Our only real proviso is that we cannot guarantee the effectiveness of STOPzilla AntiVirus. Our tests proved very encouraging, but until the software is fully audited by the likes of AV Test, there remains a question mark over its head.

Douglas Crawford

I am a freelance writer, technology enthusiast, and lover of life who enjoys spinning words and sharing knowledge for a living. You can now follow me on Twitter - @douglasjcrawf.

3 responses to “STOPzilla Security Suite review

    Hi Dr. Mouer,

    Yikes! Sounds nasty, and I feel for you! All I can say is that I did not experience these problems…

    I tried to install Stopzilla (version 7) on my new HP Touchscreen running Windows 8.1. It came with an operational trial copy of McAfee

    It slowed my machine down to a crawl. So I uninstalled it. Then several days later my trial copy of McAfee expired, and I reinstalled Stopzilla. This time the computer slowed down so much it took me hours to reach the point I could uninstall it again.

    Then I noticed that Windows fefender was still being controlled by McAfee, even though my trial version of McAfee was no longer working — so I uninstalled McAfee.

    Then I tried once more to install Stopzilla, thinking maybe it was in conflict with McAfee, even though expired. This time I got an error message “thread stuck in device driver.,” and the system started trying to auto-correct itself, continually rebooting, and giving me only 15 to 20 seconds to try something. It mist have rebooted 40 or 50 times before I finally got it in safe mode.

    In safe mode, I could not uninstall Stopzilla. So I did a system restore to a time point prior to installing Stopzilla, which got rid of Stopzilla (finally) and stopped the continual rebooting.

    Now I am just running Windows Defender. Needless to say, I am not going to install Stopzilla on this new machine. That last go around was very, very unpleasant and scary.

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