Pierluigi Paganini November 06, 2012

F-Secure  security firm has recently published the “Mobile threat report Q3/2012” related the past quarter that presents the mobile threat landscape, a scenario that has been characterized by Android’s dominance.

The rapid diffusion of Android devices has had the effect of increasing the number of malware developed for the famous OS,  during the third quarter were detected 51,447 unique samples, it is a worrying increase if we consider that Google has tried to secure it’s OS with the introduction of an additional security layer, named Bouncer, on the Android Play Store.  The Bouncer operates scanning of the existing application and for developer communities to identify malicious code but security experts have demonstrated that Bouncer protection could be eluded and probably this has also caused the explosion of infections.

Meanwhile in Q2 the malware found where maily of “drive by malware” type in Q3, between May and June, the majority of the new Android agents detected has been designed to achieve frauds based of SMS use.

A rilevant factor to consider in the analyis is the geographic distribution of malware, the large diffusion in China and Russia of such malicious code is a natural consequence of the continued high growth in Android smartphone adoption in those regions.

“In Q2, China officially surpassed the United States as the largest market for smartphones, with Android handsets accounting 81% of that market.”

At the same time in these areas has increased the ability to use apps made by third parties that are not certified and that are used as the main vehicle of infection.

Despite Android platforms is the principal target of new malware, we cannot ignore the malicious code that hit also other platforms less famous in this moment such as Symbian. Just Symbian OS has been hit by 21 new families and instances of malware in the past quarter with an increase of 17% respect previous quarter. The reason for a so sensible increase for Symbian malware is the presence of exploitable flaws in the object-capability model used in the OS.

The report highlight the similarities between the set of capabilities required by a legitimate application and the ones related to malicious software able to download and install new software from the Internet. A malware in this way is able to install and execute malicious code on a Symbian devices without  generate any alert.

Once again the privileged origin for new wave of malware is China but principal purpose is not cyber espionage but making a profit sending SMS messages to premium rate numbers or those associated with SMS-based services.

“Malware sends out SMS messages that silently sign up the device owner for a premium subscription service, incurring charges the user’s account.”

Others malware use a different fraud schema enabling WAP services on user’s mobile device to automatically access to billed services such as an on-line games.

The quarter has been also characterized by the discovery of a new variant of the famous Zeus malware for mobile environments, it is named Zitmo and targeted mobile devices. As the ancestor Zeus, Zitmo has the primary purpose to steal banking credentials in particular to capture the mobile Transaction Authentication Number (mTAN) sent by banks to their customers via SMS message and used to validate an online transaction.

Analyzing mobile threat detected in Q3 by type it is possible discover that trojan dominate the scenario with a percentage of 71,5% followed by Riskware at 7,5%, relevant are also the menaces posed by monitoring Tool, Trojan-Spy and Spyware.

Very worrying in may opinion is the raise of multiplatform malware, in particular cyber espionage tools developed to infect any kind of platforms, a valid example is the FinSpy trojan detected in the wild that is able to monitor every activities of the victims. These malware are not products of cybercrime but are designed by specialized companies that create them to support law enforcement investigations.

FinSpy is the mobile version of FinFisher, a trojan commercially marketed by Gamma International, software firm based in the United Kingdom. How is it possible that these agents are retrieved all the round the world without apparently motivation? There is a great business based on surveillance software and data proposed in the report confirms it.

Let me propose again few useful suggestions for the use of mobile devices:

• Use applications to increase the safety of the device. The principal antivirus companies are producing applications that allow even inexperienced users to avoid nasty surprises.
• Be careful visiting third party app stores. These are the favorites places for malware writers because usually every control on the quality of the apps is absent.The likelihood of you encountering malware on an alternative app store is really high.
• Avoid to downloading utility and porn applications from unverified sources because these types of apps are most likely to have malware hidden inside.
• Be careful clicking on a shortened URL in an SMS message or on a social networking site. Social network platform are preferential place for malware spreading.
• Pay attention to all interactions required by our mobile applications, make sure to authorize only necessary transactions.
• Be careful clicking on in-app advertisements. When clicking on ads, you need to confident that the ad directs to where you expect to be directed.