By now, the privacy threats posed by Amazon Alexa and Google Home are common knowledge. Workers for both companies routinely listen to audio of users—recordings of which can be kept forever—and the sounds the devices capture can be used in criminal trials.
Now, there’s a new concern: malicious apps developed by third parties and hosted by Amazon or Google. The threat isn’t just theoretical. Whitehat hackers at Germany’s Security Research Labs developed eight apps—four Alexa “skills” and four Google Home “actions”—that all passed Amazon or Google security-vetting processes. The skills or actions posed as simple apps for checking horoscopes, with the exception of one, which masqueraded as a random-number generator. Behind the scenes, these “smart spies,” as the researchers call them, surreptitiously eavesdropped on users and phished for their passwords.
The malicious apps had different names and slightly different ways of working, but they all followed similar flows. A user would say a phrase such as: “Hey Alexa, ask My Lucky Horoscope to give me the horoscope for Taurus” or “OK Google, ask My Lucky Horoscope to give me the horoscope for Taurus.” The eavesdropping apps responded with the requested information while the phishing apps gave a fake error message. Then the apps gave the impression they were no longer running when they, in fact, silently waited for the next phase of the attack.
SRLabs eventually took down all four apps demoed. As with most skills and actions, users didn’t need to download anything. Simply saying the proper phrases into a device was enough for the apps to run.
There’s little or no evidence third-party apps are actively threatening Alexa and Google Home users now, but the SRLabs research suggests that possibility is by no means far-fetched.