Elyse Betters Picaro / ZDNETFollow ZDNET: Add us as a preferred source on Google. ZDNET’s key takeaways Pixnapping could be used to steal private data, including 2FA codes.Side-channel attack abuses Google Android APIs to steal data on display.Flaw is partially patched, although a more complete fix is due in December.A new attack method demonstrated by researchers could lead to the theft of two-factor authentication (2FA) codes and more on Android devices.Also: This fundamental Android feature is ‘absolutely not’ going away, says Google – but it is changingThe attack technique, detailed in a paper titled Pixnapping: Bringing Pixel Stealing out of the Stone Age (PDF), has been developed by researchers from the University of California, Berkeley, San Diego, Washington, and Carnegie Mellon. Dubbed “Pixnapping,” this attack vector begins when a victim unknowingly installs a malicious mobile application on their Android smartphone. Notably, the app doesn’t need to abuse permissions to perform this attack, which exploits existing Android APIs, pixel rendering, and a hardware side channel. The stepsThere are three steps to Pixnapping, so-called due to its abuse of pixels rendered by a target app, such as Google Authenticator. The first stage requires the malicious app to invoke a target app and make a system call to prompt the submission of sensitive data to the Android rendering pipeline. Also: Your Android phone’s most powerful security feature is off by default and hidden – turn it on nowIn the second stage, this app will then induce graphical operations (blurring) by launching a “semi-transparent” layer on individual sensitive pixels rendered by the target app — such as the part of a screen when an authentication app renders 2FA characters. Masking is then used to isolate, enlarge, and determine the graphical nature of the pixels. The third and final stage requires the abuse of a side channel, GPU.Zip, to steal the pixels on display, one by one. In other words, the malicious app is taking pixels to capture a form of “screenshot” of content it should not have access to. More