A team of researchers, including an assistant professor at the University of California, Riverside Bourns College of Engineering, have identified a weakness believed to exist in Android, Windows and iOS mobile operating systems that could be used to obtain personal information from unsuspecting users. They demonstrated the hack in an Android phone.
The researchers tested the method and found it was successful between 82 per cent and 92 per cent of the time on six of the seven popular apps they tested.
Among the apps they easily hacked were Gmail, CHASE Bank and H&R Block. Amazon, with a 48 per cent success rate, was the only app they tested that was difficult to penetrate.
The researchers believe their method will work on other operating systems because they share a key feature researchers exploited in the Android system.
The researchers believed there was a security risk with so many apps being created by so many developers. Once a user downloads a bunch of apps to their smartphone they are all running on the same shared infrastructure, or operating system.
"The assumption has always been that these apps can't interfere with each other easily," Zhiyun Qian, of the Computer Science and Engineering Department at UC Riverside said.
"We show that assumption is not correct and one app can in fact significantly impact another and result in harmful consequences for the user," said Qian.
The attack works by getting a user to download a seemingly benign, but actually malicious, app, such as one for background wallpaper on a phone.
Once that app is installed, the researchers are able to exploit a newly discovered public side channel - the shared memory statistics of a process, which can be accessed without any privileges.
The researchers monitor changes in shared memory and are able to correlate changes to what they call an "activity transition event," which includes such things as a user logging into Gmail or taking a picture of a check so it can be deposited online.
Augmented with a few other side channels, the authors show that it is possible to fairly accurately track in real time which activity a victim app is in.
There are two keys to the attack. One, the attack needs to take place at the exact moment the user is logging into the app or taking the picture.
Two, the attack needs to be done in an inconspicuous way. The researchers did this by carefully calculating the attack timing.