ANDROIDOS_FAKEBROWS.A

 Analysis by: Kathleen Notario
 Modified by: Christopher Daniel So

 ALIASES:

Trojan-SMS.AndroidIS.FakeInst.h (Kaspersky), Android/TrojanMS.FakeInst.B trojan (Nod32)

 THREAT SUBTYPE:

Premium Service Abuser

 PLATFORM:

Android OS

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This malware uses social engineering methods to lure users into performing certain actions that may, directly or indirectly, cause malicious routines to be performed. Specifically, it disguises as a mobile web browser Opera Mini. Once the user agreed with the services of the fake browser, it sends text messages to premium numbers.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

This Trojan may be unknowingly downloaded by a user while visiting malicious websites. It may be manually installed by a user.

It bears the file icons of certain applications to avoid easy detection and consequent removal.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

DEX

Initial Samples Received Date:

29 Sep 2011

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

It may be manually installed by a user.

Installation

This Trojan bears the file icons of the following applications:

  • Opera Mini

NOTES:

This application disguises itself as the mobile web browser, Opera Mini.

Upon execution, it displays the following message:

The text translates as:

  • Title: Initialization
  • Body: Confirm agreement with the rules of loading Opera Mini. To continue downloading, click Next.
  • Button Правила: Rules
  • Button Далее: Next

When the user clicks the button Правила (Rules), the following interface is displayed:

The text in the rules describe the prices of using the services of the fake browser. Payment is made by sending text messages to premium numbers in Kazakhstan, Russia, Ukraine, Latvia, Lithuania, or Estonia.

The buttons translate to (from left to right) Back and Next. Clicking the left button (Back) will bring the user back to the first screen.

When the user clicks the button Далее (Next) in either the first or second interface, it sends the text {prefix} 1oZpW none android {suffix} to a number via SMS. {prefix}, {suffix} and the number can be any of the following:

{prefix}{suffix}Number
7539.69991
7539.4545
79fgh.7061
79fgh.1060
79fgh.4909
7539.55886
7539.4157
7539.4156
7539.4153
7539.5339
7539.2322
4722.2855
4722.9151
4722.7151
7539.1874
7539.1873
7539.1872
7539.81185
7539.81015
7830.9683
7830.9685
7539.19998866
7539.69067
7539.1945
40416.3302
40416.3303
40416.9818
40416.3302
40416.3303
ce277.8161
ce277.4449
ce277.4446
7539.930399999
7539.17013
7539.17012
7539.17011
7539.1098
7539.57575
7539.90645045
7539.7910
7539.9090150
7539.9090199
7539.5040
40416.3339
40416.3336
7539.1645
7539.1635
7539.1391
7539.72170
7539.80888
7539.7796
ce277.4107
ce277.4106

After sending SMS messages, it displays the following:

  • Title: Completion
  • Body: Activation was successful. You will receive an SMS message with the link to Opera Mini, which will be available after rebooting. If the message does not arrive, you can download Opera Mini at http://{BLOCKED}y.ru/get/1oZpW, or click Next to automatically reboot.
  • Button Выход: Exit
  • Button Открыть: Open
Clicking the button Открыть (Open), the user is directed to the URL http://{BLOCKED}y.ru/get/1oZpW

  SOLUTION

Minimum Scan Engine:

9.200

TMMS Pattern File:

1.143.00

TMMS Pattern Date:

03 Oct 2011

Step 1

Trend Micro Mobile Security Solution

Trend Micro Mobile Security Personal Edition protects Android smartphones and tablets from malicious and Trojanized applications. The App Scanner is free and detects malicious and Trojanized apps as they are downloaded, while SmartSurfing blocks malicious websites using your device's Android browser.

Download and install the Trend Micro Mobile Security App via Google Play.

Step 2

Remove unwanted apps on your Android mobile device

[ Learn More ]

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