Despite yeoman efforts by Google to close a critical hole in its Android mobile operating system that allows any app to be turned into a malicious Trojan, programs are still appearing in the company’s Google Play store with the flaw. A number of apps containing the so-called MasterKey vulnerability were discovered by cybersecurity firm Bitdefender last week.

Many of us have a wealth of decommissioned corporate-provisioned mobile devices: We’ve bought them, handed them out, and seen them used successfully for years. Now they’re on their way to the great docking station in the sky. However, because these devices are already off the books adapting them for specific security functions can mean achieving certain goals practically for free.