Thursday, March 17, 2011

Mobile Visability Limitation? There's an App for that.


Last July myself and Christian Papathanasiou presented a DEF CON 18 talk entitled "This is not the droid your looking for…". The topic of Android rootkits was widely picked up by the media, but the talk was designed around the security implication that exist when a piece a malware makes its way to a mobile device.

During our research we were successfully able to remotely obtain shell access on the device over the GSM network, read the users contacts, email, and SMS messages. Locating the device using its GPS coordinates and making a phantom phone call from the device where also demonstrated. As we noted other areas of functionality could include taking photos from the phones camera, recording from the phones mic and man-in-the-middle of apps and browser activity.

Last week, it was announced that over 50 apps in the Google Android Market were found to have malware imbedded in them. This malware is capable of data exfiltration off the victims phone. In the business world, this has major implications. How many CEO's of publically traded companies where running these apps? Maybe none, but if the malware had the capabilities that we demonstrated last summer, the implications are huge. Imagine a CEO sitting in business meetings with major clients, business partners, and even investors. The malware on that device could have the capabilities of tracking his/her physical location, and recordning the conversatons.

In the not so distant future, there will be confirmed reports of two companies are in possible merger talks, not because data “leaks” out of the corporate environment, but because there is a recording of the conversation and GPS data pinning the two CEO's at the same restaurant. Neither of the CEOs is knowling recording and disclosing these conversations, but one of their mobile phones has malware on it.

With all the news today around the weakness of the Android Market submission process, it is important to understand that this problem is just limited to the Android platform, but also impacts the iOS platform as well. Last fall SpiderLabs' Eric Monti demonstrated at ToorCon 12 that you could apply these same techniques to an iPhone and install a backdoor or other piece of malware. This is accomplished by using a technique used to jailbreak a device. In the case of malware, the jailbreak turned against the end user as an exploit to gain the attacker root privileges on the device. The window of exposure on "jailbreak-able" iOS devices is very large. Seemly hours after a new version of the iOS is released, a jailbreak is available, not to be "fixed" until the next release several months later. It is important to note that a “jailbreak” is equal to a root compromise. In Eric’s research, he showed it as a silent drive-by installation requiring no user interaction.

The Android Market isn't the only mobile app shop where there is no security or content validation occurs. Many users jailbreak their iOS devices so they can install and run apps that have not been approved by Apple. Once a user has jailbroken their iOS devices, they can download apps from a marketplace called Cydia. What has recently happened in the Android Market can easily happen in Cydia, if it hasn't already. (Is anyone searching there?) This would allow a malicious developer to publish an application with malware, botnet or rootkit functionality to the jailbreak community. Given, I have run into CTO’s of security vendors that have jailbroken iPhones, this threat isn’t just limited to the tech hobbyist.

By design mobile devices place a strong layer of abstraction between the end user's interface and the underlying Operating Systems. This means that there could be a rootkit, backdoor or botnet running at the OS layer and the end user would have both no indication of its presence nor would they be able to detect its activity with the limited aid of the various security software applications on the market.



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