DroidDream autopsy: Anatomy of an Android malware attack

The Android world is still reeling from the DroidDream invasion of the Android Market. Google has flipped the kill switch to wipe out apps associated with DroidDream, but the work of investigating how this Android Trojan infiltrated Google, and how to prevent similar attacks in the future is just beginning.

Lookout–a mobile security company with tools to protect Android smartphones–has been diligently exploring the DroidDream apps to figure out what makes this malware tick. First and foremost, DroidDream is a Trojan attack that is hidden within seemingly legitimate apps. What makes it more insidious than other Android Trojans is that DroidDream managed to weasel its way into the actual Android Market. Let’s break down what else we know about this threat:

• The malware is aptly named because it is designed to only run while the Android smartphone owner is sleeping–ostensibly dreaming peacefully. DroidDream is configured to do its dirty work between 11pm and 8am.

• DroidDream relies on two known exploits–exploid and rageagainstthecage–to break out of the Android security sandbox. Ironically–both of the targeted vulnerabilities were patched in Android 2.3 “Gingerbread”. In this case, Android’s fragmentation proved to be an Achilles heel because–although Gingerbread has been available for a couple months–less than one percent of all Android smartphones have received the update. Android users are at the mercy of individual smartphone vendors to deploy the Android OS update for their specific smartphone model.

• Once the Android smartphone is rooted, DroidDream searches for a specific package named “com.android.providers.downloadsmanager”. If the package is not found, DroidDream silently installs a second malicious app without the user’s knowledge. Other malicious apps can be installed in stealth from the DroidDream command and control servers.

• DroidDream sends a variety of information from the smartphone to the remote command and control center, including: IMEI, IMSI, device model, SDK version, language, country, and user ID.

Lookout has found that DroidDream is a powerful zombie agent that can silently install any applications and execute code with root privileges at will. According to Lookout, DroidDream is also the first piece of Android malware that uses an exploit to gain root permissions and assume virtually limitless control of the infected smartphone.

The elephant in the room, though, is the fact that DroidDream exploits vulnerabilities that have already been identified and patched, but that 99 percent of Android users are still exposed because their smartphone has not yet been graced with the update to Gingerbread.