TechRepublic investigated the issue and reports that HCK Partners, the company that send out the press release on behalf of Trend Micro, clarified that the majority of the problem apps were found in places other than Google Play and that no fake app was found in Google Play. It seems the person who wrote the press release was a little overzealous and wrongly accused Google Play of housing malware:
Apparently, the individual who wrote this release was more than a little overzealous with their charges of rampant malware in the Google Play Store. There's a clear disconnect between the subject line of the release, "Google Play populated with fake apps, with more than half carrying malware," and the company's follow-up statement, "Note that the fake apps samples we gathered are from third party sources and none was found in Google Play".
To state that "77 percent of the top 50 apps on the Google Play store have repackaged or fake apps associated with them" is significantly different than saying 77% of Android apps coming from third-party sources contain malware. And even then, a third-party source could easily include the Amazon app store. Claims like these need facts and sources. Where were these fake apps found? Which specific apps were they?