Based on our testing, the best paid Android antivirus app is Bitdefender Mobile Security ($15 per year), which offers nearly flawless malware protection with a wide assortment of other features. The freemium Norton Mobile Security has similarly excellent protection, and doesn't hold back much from free users who don't want to pay the premium price of $25 per year.
Avast Mobile Security and CM Security Master each offer a rich assortment of features, even in their free versions, and generally score highly in malware-detection tests. But Avast's anti-theft and call-blocking features didn't work well for us, and CM Security Master's malware-detection rates varied quite a bit from month to month. (CM Security Master has also been criticized for allegedly oversharing user data with advertisers.)
You'll be taking a chance with the other two apps we reviewed. Lookout Security & Antivirus was one of the first mobile antivirus apps, and it has a good reputation among Android users. But the company no longer submits the app to independent testing labs, so we really don't know how well it protects against Android malware.
The other app, PSafe DFNDR, is easy to use and full-featured, and its paid version is only $4.99. But in lab tests, its malware-detection rates bounced up and down like a yo-yo. We can only hope that PSafe gets those issues straightened out before our next round of Android antivirus app reviews.
The best mobile antivirus apps offer not only top-notch malware detection and prevention, but also a range of privacy and anti-theft features. These include the ability to back up your contacts and photos, track your phone or tablet via GPS, snap a picture of a phone thief with the device's camera, send commands to a lost or stolen phone via text messages and even use your Android Wear smartwatch to locate your phone.
Latest Security Alerts and Threats
— Google recalled its wireless Titan security keyfobs (sold outside the U.S. by Feitian) after a security vulnerability was discovered. ADVICE: Log into your Google account in a web browser and check https://myaccount.google.com/replacemykey. If your security key is affected, the page provides replacement instructions.
— Commercial spyware was discovered targeting WhatsApp for Android, iOS, Windows Phone and Tizen, turning the mobile app into a spying device. ADVICE: Update your WhatsApp installation to the latest version, which should close the security hole.
— Nearly three dozen models of Linksys Wi-Fi routers may be leaking sensitive information about the computer, smartphones, printers and other devices on users' home networks. It's not clear if Linksys' firmware patch works. ADVICE: If nothing else, make sure the administrative username and password on your Linksys router are not the factory defaults. Then wait for a new firmware patch.
How We Tested
To gauge security protection, we used the latest evaluation results from AV-TEST, an independent lab in Germany that rates major Android security apps every two months based on their ability to detect zero-day malware and other recent threats. Because some apps' results are inconsistent from one test to the next, we've also looked at the past year's worth of AV-TEST results.
To measure the impact these security apps have on overall performance, we used the Geekbench 6 benchmarking app on a Samsung Galaxy S8 phone running Android 7.0 Nougat. For each app, we ran Geekbench several times with no AV app installed, then with one of the review apps installed and finally during that app's full scan.
We also evaluated the number and usefulness of each app's features, took note of which features were reserved for paid users, and assessed the user interface and installation process.
Bitdefender's Android security app offers nearly flawless malware protection, minimal performance impact and robust privacy-protection tools, while incorporating Android Wear watches into the app's anti-theft features. However, there are no scheduled malware scans, and there's no freemium option. (The separate Bitdefender Antivirus Free for Android only scans for malware.) But at $15 per year per device, Bitdefender Mobile Security is well worth the expense.
Norton Mobile Security offers terrific malware protection, and its call-blocking, text-blocking and contacts backup features are free for all users, as is the excellent anti-theft functionality. The premium yearly license has dropped to $25 and protects up to 10 devices. Norton's best paid feature is App Advisor, which checks installed software and apps in the Google Play store for security and privacy risks. Also good are Norton's app lock and password manager, both of which are free, stand-alone apps. There's also a new VPN app, but it's an extra $30 per year.
Avast Mobile Security & Antivirus is one of the most full-featured Android security apps on the market, including everything from a privacy advisor to a VPN client to a customizable blacklist. But while Avast's malware protection has improved, some of its otherwise excellent anti-theft functions didn't work for us, and its call-blocking feature barely worked at all.
CM Security's new paid version costs $36 per year, adds an unlimited VPN client and kills third-party ads. However, the rest of the app's extensive set of features and options can still be had for no price whatsoever. There's a network scanner; a clean, easy-to-use interface; an app lock; and a call blocker. But CM Security's malware-detection rates fluctuated from month to month, its anti-theft features offer little more than the built-in Android Device Manager, the free version displayed a lot of ads and the company has been accused of using its mobile apps in a click-fraud scheme.
Lookout's Android antivirus app was one of the first, and its ease of use and functionality explain its popularity among Android users. There's a free tier; a regular premium tier for $30 per year, which has many features other Android security apps offer for free; and a "premium plus" plan that, for $100 per year, contains a full identity-protection service. But Lookout no longer submits its app to independent labs for testing, so we don't know how well it protects against malware.
We want to like PSafe DFNDR. It looks great; has many useful features, all of which are free; and its paid version costs only $4.99 per year and merely removes ads. But in lab tests, its malware-detection rate changes from month to month. Sometimes it's excellent, sometime it's pretty bad. Until PSafe gets that problem ironed out, we have to recommend other apps.