According to Google's new Android ecosystem transparency report, you're probably running Android Lollipop (5.0) as opposed to Android Pie (9). The same report shows that if you sideload apps, you're almost seven times more likely to be infected than if you stick to Google Play as your app source. Malware-infected users
Google calls malware PHAs, or potentially harmful apps. Android version, but entirely innocuous on another version. Leapipop, but if you have the same app on a phone running Android Pie, new security measures could be rendered it completely safe.  Google's Security Report Shows A Clear Pattern Among Malware-Infected Users ”
PHA rates by Android version. Image via Google Transparency Report
Looking at the chart above, you may be running the new Android versions. But these are percentages of devices infected by malware, so total number of users has no impact. The Lollipop PHA rate is 0.66%, while the PHA rate is 0.06%.
The difference in PHA rates is almost as long as you staggering sideload apps from external sources. Google Play users are infected at 0.9% globally.
PHA infection rates by country, and the results are surprising. Indonesia and India (gold and green lines, respectively) had the worst rates at 0.65%, but the United States (black line) was third-worst at 0.53%. You'd better be on the Android Android Marketplace than you would expect to
More instances of sideloading apps per user, and more phones from OEMs with bad Android update track records.
With Samsung being notoriously slow for Android updates, they have some of the blame for poor malware rates in the US. They're in the middle of Android and they have just released their Android OS to Oreo, an OS upgrade that was made available 15 months ago.
While there's nothing you can do about receiving this update (aside from rooting and installing a custom ROM), you can certainly improve your security by being aware of sideloading apps. APKMirror or a dependable developer's official website.