How Cloud Antivirus Software Works

cloud antivirus
Just how vulnerable is your cloud computer network? Aitor Diago/Getty Images

Whether you have years of computing behind you, or you've just bought your first laptop or desktop PC, tablet or smartphone, you've probably already heard about the dangers of not protecting yourself from malware — viruses, worms, trojans and other programs used by hackers to damage computers and other devices, steal your personal data, hijack your machine and turn it into a bot, or even lock up your device and hold it for ransom. [source: Fruhlinger]

To protect yourself from such threats, you need security software. One increasingly popular option is to use a cloud antivirus product. In contrast to a conventional antivirus program, cloud antivirus does most of its processing on the internet rather than your computer's hard drive.


Cloud antivirus software consists of client and web service components working together. The client is a small program running on your local computer, which scans the system for malware. Full locally installed antivirus applications are notorious resource hogs, but cloud antivirus clients require only a small amount processing power. Instead, the heavy lifting is done by software running on cloud servers, which continually update their lists of malware files and risky websites. Cloud antivirus is capable of transmitting real-time data on those threats to your device, so that you don't have to rely upon manual or scheduled automatic updates to keep your defenses up-to-date. [source: Kapersky]

Cloud antivirus can provide more powerful protection for your devices, and it has numerous other benefits as well. Here are a few:

  • Your malware database is updated without the need to download all the signatures — the clues that a program is malicious — on your device.
  • The service can do behavioral-based scanning, which can spot new threats.
  • Less demand on your device's storage space and memory.
  • The ability to use artificial intelligence, machine learning and other advances, so that your protection evolves with the threats [source: Steinberg].

Cloud antivirus has some disadvantages, too. One drawback is that you have to remain connected to the internet, and if your connection is slow, that can interfere with files being scanned. And since everything is checked against cloud databases, some scans may take longer [source: Steinberg].

In this article, we'll tell you more about the features of cloud antivirus programs and how you can use them to protect your devices.


Cloud Antivirus Features

If you have any experience using antivirus software, the user interface (UI) of cloud antivirus software should look familiar. After all, its primary job is the same as any other antivirus application: scanning your computer to identify and clean up any malware. Therefore, you'll find these common functions in a cloud antivirus UI:

  • Scan the entire computer or certain folders on the computer.
  • Adjust when to make automatic scans and what files to include in them.
  • View detailed reports to see what malware was detected during a scan.
  • Take actions to remove or restore any quarantined files, or files that were neutralized in some way until you decide to restore or delete them.

The unique features in cloud antivirus are those you won't see in the UI. We've already seen that cloud antivirus splits its tasks between your computer (a client application) and web servers elsewhere on the internet. Because of this split personality, cloud antivirus can leverage resources from across the internet to better defend your computer against malware. For each cloud antivirus product, these resources come together to form a central database of malware data.


Malware is detected in different ways, depending upon the antivirus program. One method is signature-based detection, in which the program spots a piece of code that's known to be the fingerprint of a attacker. Another technique is heuristics-based detection, in which the antivirus program looks for characteristics, such as unusual instructions, when it's scanning files. Antivirus programs also watch suspicious actions by programs, such as the monitoring of keystrokes, a technique known as behavioral detection.

Cloud-based antivirus programs can make these techniques more powerful, because they're also capable of learning from what's happening on the computers of various users across the internet and then quickly using that information to protect everyone [source: Zeltzer]

In the next section, we'll describe how this works with one popular cloud antivirus product, TotalAV.



These days, cloud antivirus programs often provide protection for multiple devices, from PCs to smartphones, and increasingly offer an array of services in addition to basic protection. One example is TotalAV, which offers cross-platform security software that can protect computers running either Microsoft Windows or the Mac OS, in addition to iPhones and iPads and Android devices [source: TotalAV]. There's a free version as well as the paid product with full features [source: TotalAV].

In addition to safeguarding devices against viruses in real time, TotalAV offers protection against phishing scams, ransomware, adware and spyware, as well as an ad blocker, a password vault and access to a virtual private network (VPN) for privacy protection. There's also Web Shield, function that warns a user about websites that may be hazardous to visit because they host malware. It even includes system turn-up optimization tools and a disk cleaner to free up system space. [source: TotalAV].


After you download a trial version from the TotalAV website, you'll be prompted to install the program and follow some instructions. Once the program is installed, you'll see a main screen that allows you to setup realtime protection and activate various features, such as the password vault. In addition, you'll be able to run a "Smart Scan," which checks for malware, security and privacy issues, performance issues, and unneeded duplicate files on your device, all with a single click [source: TotalAV].

Smart Scan will generate a list of potentially dangerous files on your device and the malware threat they're associated with, and also offer the option of quarantining those files. The scan also will reveal tracking cookies that have been implanted on the device, as well as potentially unwanted applications and autorun programs, and will make recommendations for measures to improve your security [source: TotalAV].

In the next section, we'll list some other cloud antivirus products.


Products and Challenges

Here are a few of the other cloud antivirus products on the market.

  • Webroot Secure Anywhere AntiVirus: This program for PCs, Macs and Android devices stores malware definitions in the cloud and says that it has "a more robust threat library than our competitors. " In addition to the basic single device price, there's also a package deal that offers coverage for up to three devices plus WiFi Security, which includes VPN to protect users when they're on a network, as well as web filtering to protect from risky websites.
  • Immunet Free Antivirus: This cloud antivirus software for Windows PCs focuses upon "community-based security," so that when one community member encounters malware, Immunet automatically adds that protection for the rest of its users. Immunet's website emphasizes compatibility with other antivirus software installed on a PC, so that it can provide an extra layer of protection. In addition to its free consumer-grade product, Immunet also has a business product that can extend protection across PCs, Macs, Linux systems, mobile devices and even virtual environments.
  • HitmanPro.Alert: This cloud-based consumer antivirus product, now a part of network security company Sophos, is advertised as providing an extra layer of protection around software such as Microsoft Office, and also includes CryptoGuard, a feature that analyzes any encryption that takes place on your computer, in an attempt to stop ransomware attacks. It also encrypts keystrokes online and even tries to make its users appear to be malware researchers, a trick that chases away hackers. There's a trial version available.

Cloud antivirus skeptics argue that this approach to malware protection lacks some essential components for security and performance. One concern is the potential invasion of privacy because of the collected data from your computer. Some products may be a bigger threat in this respect than others. Before you decide on any cloud antivirus product, be sure to find out what data from your computer could become part of its collective database.


Performance arguments include some of the same concerns you might have about traditional antivirus software. For example, cloud antivirus software could increase the time required to start or shut down your computer or slow down the overall performance of other applications. It's possible, though, that this might still beat the impact of some traditional antivirus programs. Determine whether a cloud antivirus product's performance is acceptable to you by trying out the software on your computer through your day-to-day activities. For most cloud antivirus products, giving it a try won't cost you anything!

HowStuffWorks may earn a small commission from affiliate links in this article.


Frequently Answered Questions

What is cloud-based anti virus?
Cloud-based anti virus is a type of antivirus software that uses cloud computing to protect a user's computer from malware. Cloud-based anti virus works by scanning a user's computer for malware and then sending the results of the scan to a remote server. The remote server then analyzes the results and determines if the user's computer is infected with malware. If the remote server finds that the user's computer is infected, it will take appropriate action to remove the malware from the user's computer.
Can antivirus software be cloud-based?
Yes, antivirus software can be cloud-based. Cloud-based antivirus software typically uses a subscription model, which means that users must pay a recurring fee to use the software. Cloud-based antivirus software may offer additional features, such as real-time protection against new threats and automatic updates.
Is cloud-based antivirus good?
The effectiveness of a cloud-based antivirus solution depends on a number of factors, including the specific features and capabilities of the solution, the quality of the cloud service provider, and the organization's overall security posture. However, in general, cloud-based antivirus solutions can be an effective way to protect against malware and other threats.

Lots More Information

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