Android Threat Trend Shows That Criminals are Thinking Outside the Box

A quick online search would reveal a number of articles declaring any one of the last few years as being the “year of mobile malware.” Conversely, these searches also reveal claims that the same years are not going to be the year of mobile malware. These search results go back as far as the early part of the decade. The contradictory nature of these bold predictive headlines could be explained by the fact that the articles are typically written at the beginning of each year—and who knows what the year may hold at the outset?

But, if the criteria to qualify 2011 as the real "year of mobile malware" was to be challenged, then surely the events of the past few weeks alone should be enough to justify the fact that this year truly has seen considerable seismic activity that has shifted the tectonic plates of the mobile threat landscape.
 
 types and targets
Figure 1 - Mobile malware, 2011: types and targets
 
The message that is coming through loud and clear is that the creators of these threats are getting more strategic and bolder in their efforts. We are seeing increased attempts to complicate the infection vectors of mobile malware to the point where a simple uninstall is insufficient.
 
Multiple payloads
 
One such strategy is to separate the malicious package into staged payloads. The idea is simple: instead of having one payload that carries all of the malicious code for any given attack, break the threat into separate modules that can be delivered independently. There are several advantages to deploying the threat in this way. First, it obviates the tell-tale sign of a huge, overzealous permissions list accompanying the installation of the threat, which may alarm the user as to the intention of the malicious app. Secondly, smaller pieces are easier to hide and inject into other apps. Furthermore, dispersing the attack across separate apps complicates the integrated revocation processes from the service provider, marketplace, etc. 
 
Dispersed payload process of mobile threat
Figure 2 - Dispersed payload process of mobile threat
 
A textbook example of this is the newly discovered variant of Android.Lightdd. Apart from a few minor variations, such as the service name running in the background now being called “Game Services” and the three new domain names that it attempts to connect to, everything else remains the same as the previous samples discovered last month. This includes the encryption routine and the keys used to hide data within the threat.
 
Data-gathering process of Android.Lightdd
Figure 3 - Data-gathering process of Android.Lightdd
 
This threat is the first stage in a multi-payload delivery system, responsible for reconnaissance and intelligence gathering (model, language, country, IMEI, IMSI, OS version) on the compromised device, which precedes the downloading of additional payloads. 
 
 "Game Services" running in Android.Lightdd
Figure 4 -  "Game Services" running in Android.Lightdd
 
An interesting fact is that the threat was capable of downloading additional components and updates through official channels of distribution as well as Internet/direct downloads. At the time of writing, all of the hosts associated with the threat are offline.
 
 
Example of additional components and updates through official channels of distribution
Figure 5 - Example of additional components and updates through official channels of distribution
 
 
Overcoming the user acceptance hurdle
 
As with its previous variant, Android.Lightdd still requires the user to accept the installation of any download—a major obstacle in this model of delivering a payload. However, another threat also discovered in the wild, Android.Jsmshider, has found a way to overcome this obstacle.
 
By signing the payload with an Android Open Source Project (AOSP) certificate, the threat was capable of performing further downloads without any interactions or prompts, as the underlying device considered the payload to be a system update by virtue of the accompanying certificate. At this point, however, this deception only works for custom modifications.
 
Example of Android.Jsmshider exploiting Android Open Source Project certificate
Figure 6 - Example of Android.Jsmshider exploiting Android Open Source Project certificate
 
Given the relatively elaborate installation of this threat, you would think that the final payload being deployed would rival something akin to the Stuxnet worm, but in fact, the final payload in the majority of cases was nothing more than a garden-variety premium SMS sender. Premium SMS senders and/or dialers don’t get a lot of respect from antivirus researchers, mainly because they lack sophistication and, just like those emails that we all get from a distant contact promising us a cut in the deal of a lifetime, depend largely on social engineering for a payoff. But, they have been around for ages and, as far as mobile threats go, have the quickest ROI for their authors. 
 
There is plenty of research demonstrating that the average price of a stolen credit card (due to competition and market forces, etc.) has dropped to as low as $0.40 – $0.80 (USD) per unit. In contrast, the latest dialer to be discovered that was targeting North America would pay the author $9.99 per successful install and execution. Furthermore, if the threat is not detected by the user, each subsequent execution would result in a continuous revenue stream—until the owner of the device saw his or her next phone bill, that is.
 
Another interesting trend that Symantec has observed is the use of in-app features that facilitate the promotion and/or download of other apps. In some cases, we have seen this implemented as full-fledged browsing access to another third-party app store that has been embedded as undocumented functionality of the original app that the user has downloaded from the official marketplace—without any indication that the victim is downloading or browsing apps from another website or store.
 
Example of in-app features that facilitate the promotion and/or download of other apps
Figure 7 - In-app features that facilitate the promotion and/or download of other apps
 
Even though user interaction is required to install additional apps, there is a concern that this vector has an element of social engineering, whereby the user assumes that, since the first app was downloaded through an official channel, any additional apps must also be originating from there, too. Since there is no indication to the user that he or she is downloading from a third-party site, an element of trust might be established with this particular vector.
 
All things considered, the real question that comes to mind is: if this truly is the “year of mobile malware,” where do we go from here?

Android Threat Set to Trigger On the End of Days, or the Day’s End

Symantec has discovered a Trojanized version of a legitimate application that is part threat, part doomsayer. The threat was embedded in a pirated version of an app called ‘Holy ***king Bible’, which itself has stirred controversy on multiple forums in which the app is in circulation.

Once the threat is installed, it waits for the device to reboot. After the reboot, it starts a service called 'theword'. At regular intervals, it attempts to contact a host service, passing along the device’s phone number and operator code. It then attempts to retrieve a command from a remote location. These same actions are carried out in a loop, in intervals of 33 minutes. In addition to having abilities to respond to commands through the Internet and SMS, the threat also has activities that are designed to trigger on the 21 and 22 of May 2011, respectively.

There are multiple suggestions in the threat that indicate that it was aimed at users in North America. One obvious element is that the threat was checking the US date format (MMDDYYYY) and will only trigger activation if the date is “05222011”, as opposed to “22052011” etc.

Another hint includes the cultural (borderline bizarre) reference in the threat, which is geared more towards an audience in the North American region. Additionally, it attempts to register users as members of a US-based political action committee called ColbertPAC. Lastly, and most evidently, is that the ‘End of the World’ occurring on May 21 is a phenomenon largely limited to North America.

And then on the 21 day of May 2011 AD….

As soon as the threat recognizes the date is May 21, 2011, it creates a database called “mydb.db”:

It then writes the string “endoftheworld” to the table ‘myTable'. (This is used as a trigger to tell the 'SMSsmack' class to automatically reply back to any SMS sent to the device with the message below.) Next, it randomly picks one of several pre-defined messages and proceeds to send the spam to the entire contact list:

Lastly, the wallpaper is changed to the following image:

When the threats detects that the date has rolled over to May 22, it changes the wallpaper again and spams the contact list with a new message:

Symantec has added detection for this threat, which is known as Android.Smspacem.

To avoid becoming a victim of such malicious Android applications, we recommend that you only use regulated Android marketplaces for downloading and installing Android applications. By default, an Android device does not allow the installation of applications from unknown sources (i.e. non-Market). This default configuration helps protect against rogue, pirated apps that may be malicious. The user must manually change this setting to allow the installation of unofficial (non-Market) applications, also known as side-loading. Checking user comments on the marketplace can also assist in determining if the application is safe. Lastly, always check the access permissions being requested during the installation of any Android applications. If they seem excessive for what the application is designed to do, it would be wise to stop installing the application.

A special thanks to Kaoru Hayashi for the in-depth analysis of this threat.

What Does the Consumerization of IT Mean to You? (An End-User Survey on Personal and Business Smartphone Trends)

More than ever before, smartphones are keeping us connected both personally and professionally. Because most of us have a preference as to the ideal smartphone, IT departments are increasingly being tasked with managing a mix of business-liable and employee-liable devices. This trend has become known as the consumerization of IT.

Symantec has developed a short survey to get smartphone end users’ perspectives on this trend. We’d also like to learn more about how your employer is managing the growing use of smartphones, especially those being purchased and brought into the organization by employees. The quick five minute survey can be found here: http://bit.ly/gsdgmX

Once you’ve taken the survey, please stay tuned to the original post that resides in the Security Community Blog. We’ll be sharing the results once the survey is complete.