As you will probably know my Birthday post for Android Malware has deserved a mention from Engadget and Wired. Easily predictable but not for me, the Engadget link has been flooded by comments posted by Android supporters and adversaries, with possible trolls’ infiltrations, up to the point that the editorial staff has decided to disable comments from the article. The effect has been so surprising that someone has also insinuated, among other things, that I have been paid to talk s**t on the Android.
Now let me get some rest from this August Italian Sun and let me try to explain why I decided to celebrate this strange malware birthday for the Android.
First of all I want to make a thing clear: I currently do own an Android Device, and convinced, where possible, all my relatives and friends to jump on the Android. Moreover I do consider the Google platform an inseparable companion for my professional and personal life.
So what’s wrong? If you scroll the malware list you may easily notice that the malware always require an explicit consent from the user, so at first glance the real risk is the extreme trust that users put in their mobile devices which are not considered “simple” phones (even if smart), but real extensions of their personal and professional life.
You might say that this happens also for traditional devices (such as laptops), but in case of mobile devices there is a huge social and cultural difference: users are not aware to bring on their pocket dual (very soon four) cores mini-PCs and are not used to apply the same attention deserved for their old world traditional devices. Their small display size also make these devices particularly vulnerable to phishing (consider for instance the malware Android.GGTracker).
If we focus on technology instead of culture (not limiting the landscape to mobile) it easy to verify that the activity of developing malware (which nowadays is essentially a cybercrime activity) is a trade off between different factors affecting the potential target which include, at least its level of diffusion and its value for the attacker (in a mobile scenario the value corresponds to the value of the information stored on the device). The intrinsic security model of the target is, at least in my opinion, a secondary factor since the effort to overtake it, is simply commensurate with the value of the potential plunder.
What does this mean in simple words? It means that Android devices are growing exponentially in terms of market shares and are increasingly being used also for business. As a consequence there is a greater audience for the attackers, a greater value for the information stored (belonging to the owner’s personal and professional sphere) and consequently the sum of these factors is inevitably attracting Cybercrooks towards this platform.
Have a look to the chart drawing Google OS Market share in the U.S. (ComScore Data) compared with the number of malware samples in this last year (Data pertaining Market Share for June and July are currently not available):
So far the impact of the threats is low, but what makes the Google Platform so prone to malware? For sure not vulnerabilities: everything with a line of code is vulnerable, and, at least for the moment, a recent study from Symantec has found only 18 vulnerabilities for Google OS against 300 found for iOS (please do no question on the different age of the two OSes I only want to show that vulnerabilities are common and in this context Android is comparable with its main competitor).
Going back to the initial question there are at least three factors which make Android different:
- The application permission model relies too heavily on the user,
- The security policy for the market has proven to be weak,
- The platform too easily allows to install applications from untrusted sources with the sideloading feature.
As far as the first point is concerned: some commenters correctly noticed that apps do not install themselves on their own, but need, at least for the first installation, the explicit user consent. Well I wonder: how many “casual users” in your opinion regularly check permissions during application installation? And, even worse, as far as business users are concerned, the likely targets of cybercrime who consider the device as a mere work tool: do you really think that business users check app permission during installation? Of course a serious organization should avoid the associated risks with a firm device management policy before considering a wide deployment of similar devices, most of all among CxOs; but unfortunately we live in an imperfect world and too much often fashion and trends are faster (and stronger) than Security Policies and also make the device to be used principally for other things than its business primary role, hugely increasing risks.
This point is a serious security concern, as a matter of fact many security vendors (in my opinion the security industry is in delay in this context) offer Device Management Solution aimed to complete the native Application Access Control model. Besides it is not a coincidence that some rumors claim that Google is going to modify (enhance) the app permission security process.
As far as the second point is concerned (Android Market security policy), after the DroidDream affair, (and the following fake security update), it is clear that the Android Market Publishing (and Security) model needs to be modified, making it more similar to the App Store. There are several proposals in this context, of course in this place is not my intention to question on them but only to stress that the issue is real.
Last but not least Sideloading is something that makes Android very different from other platforms (read Apple), Apple devices do not allow to install untrusted apps unless you do not Jailbreak the devices. Android simply needs the user to flag an option (By The Way many vendors are opening their Android devices to root or alternate ROMs, consider for instance LG which in Italy does not invalidate the Warranty for rooted devices) or HTC which, on May 27, stated they will no longer have been locking the bootloaders on their devices.
So definitively the three above factors (together with the growing market shares) make Android more appealing for malware developers and this is not due to an intrinsic weakness of the platform rather than a security platform model which is mainly driven by the user and not locked by Manufacturer as it happens in case of Cupertino.
There is a new nightmare on the Android Market, and again many Android devices are not going to have a good awakening.
The last security advice for the Google Mobile OS comes from Lookout, which has discovered a new variant of the infamous DroidDream, the first malware conveyed by the Official Android Market capable of infecting at the beginning of March, according to Symantec, between 50.000 and 200.000 devices.
This time the brand new version, dubbed DroidDreamLight, was found in 26 repackaged applications from 5 different developers distributed in the Android Market. According to Lookout DroidDreamLight is no less than is “noble” predecessor, since was able to affect between 30.000 and 120.000 users.
According to Lookout, the malicious components of DroidDream Light are invoked on receipt of an android.intent.action.PHONE_STATE intent (e.g. an incoming voice call). As a consequence DroidDream Light does not depend on manual launch of the installed application to trigger its behavior. The broadcast receiver immediately launches the <package>.lightdd.CoreService which contacts remote servers and supplies the IMEI, IMSI, Model, SDK Version and information about installed packages. It appears that the DDLight is also capable of downloading and prompting installation of new packages, though unlike its predecessors it is not capable of doing so without user intervention.
The list of the infected applications (already removed from Google) is available at the original link. I must confess I could not help noticing the rich amount of “hot” applications, which confirm (unfortunately) to be a lethal weapon for carrying malware.
This event will raise again the concerns about the security policies on the Android Market, and about the apparently unstoppable evolution of the mobile threat landscape which has brought for the Android a brand new malware capable of sending data to a remote server. A further step closer to a mobile botnet even if, at least for this time, with limited capabilities of auto-installing packages,.
I will have to update my presentation, meanwhile do not forget to follow the guidelines for a correct mobile behavior:
- Avoid “promiscuous” behaviours (perform rooting, sideloading or jaibreaking with caution, most of all in case of a device used for professional purpose);
- Do not accept virtual candies from unkown virtual individuals, i.e. only install applications from trusted sources, always check the origin and their permissions during installation;
- Beware of unusual behavior of the phone (DroidDream owes its name to the fact that he used to perform most of its malicious action from 11 P.M to 8 A.M.);
- Beware of risks hidden behind social Network (see my post of yesterday on mobile phishing);
- Use security software;
- Keep the device updated.
- DroidDreamLight malware hits dozens of Android apps (venturebeat.com)
- Malicious apps removed from Android Market (news.cnet.com)
- Malicious apps removed from Android Market (news.cnet.com)
- Lookout Teams Pegs 25 Android Market Apps Infected With DroidDreamLight Malware (androidpolice.com)
- 30,000 to 120,000 Android Users Affected by New Variant of Droid Dream Malware (readwriteweb.com)
- New Android malware spotted: DroidDream Light (intomobile.com)