Google has removed over 500 apps that included mobile games for teenagers from its Play Store on account of a spyware threat.

The decision came after US-based cyber-security firm Lookout discovered more than 500 apps that could spread spyware on mobile phones, Fortune reported late on Wednesday.

According to Lookout, the apps used certain software that had the ability to covertly siphon people's personal data on their devices without alerting the app makers.

The impacted apps included mobile games for teenagers, weather apps, online radio, photo editing, education, health, fitness and home video camera apps.

The researchers discovered that the 'Igexin' advertising software development kit (SDK) embedded in the apps caused these to communicate with outside servers that had earlier spread malware.

The bug in SDK was discovered when an app appeared to be downloading large, encrypted files from those servers.

While app developers are required to notify users on how data is collected, it is possible that they did not know that the Igexin SDK could open the door to malware.

Many of the developers of the impacted apps were unaware of the security flaws, the report added.

Lookout researchers said once they notified Google of the security flaws they found, the software giant followed up by removing the apps from the Play Store.

These apps have been replaced with new versions that do not have the same cybersecurity vulnerabilities.

As per the Fortune report, Google and Apple also recently removed over 330 financial trading apps from their online stores following a review by the Australian Securities and Investments Commission.

These financial apps, the Australian regulator discovered, did not have appropriate licenses required and failed to disclose financial risks to their users.