Even though the Google Play Store is by far the safest place to download apps for your Android smartphone or tablet, there’s always the danger of installing one that is not what it claims to be. Recently, Google removed such an app from the Play Store that was labeled as “System Update”. In fact, the app was spyware that had been downloaded millions of times in the past few years.

The security firm¬†Zscaler claims it discovered that this “System Update” app, which first launched in 2014, was spyware that sent data about a device’s location to whomever created the app. It also can look at certain incoming SMS messages. The security firm says that if a user installed and tried to use the app, it would appear to quit working and show the message, “Unfortunately, Update Service has stopped.” In fact, there is evidence the app would continue to work in the background.

The firm alerted Google to this fake app, and the company has since removed it from the Play Store, but not before the listing’s page indicated it had been downloaded between 1 million and 5 million times. It goes without saying that all Android device owners should be careful when downloading any app from the Play Store. In this case, there were clues that “System Update” was a fake. There were no screenshots posted in its Play Store listing, and there was no proper description of the app. Finally, written reviews in the listing were highly negative, as many users stated the app didn’t work.