Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.



03 February 2012
08 February 2012
Infection Length:
195,990 bytes
Systems Affected:
CVE References:
Android.Bmaster is a Trojan horse on the Android platform that opens a back door, downloads files and steals potentially confidential information from the compromised device.

Android package file
The Trojan may arrive as an APK package with the following characteristics:
Service Name
Process Name

Antivirus Protection Dates

  • Initial Rapid Release version 03 February 2012 revision 022
  • Latest Rapid Release version 19 February 2013 revision 016
  • Initial Daily Certified version 03 February 2012 revision 036
  • Latest Daily Certified version 07 February 2012 revision 005
  • Initial Weekly Certified release date 08 February 2012
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.
Android package file
The Trojan may arrive as an APK package with the following characteristics:

Service Name


Process Name

When the Trojan is being installed, it requests permissions to perform the following actions:
  • Access information about networks
  • Access information about the WiFi state
  • Access location information, such as GPS information
  • Allow access to low-level power management
  • Allow access to low-level system logs
  • Allows access to hardware peripherals
  • Allows access to install and uninstall shortcuts
  • Allows access to the camera and the camera's flash
  • Allows access to the list of accounts in the Accounts Service
  • Allows an application to delete cache files
  • Allows an application to get information about the currently or recently running tasks
  • Allows an application to modify the current configuration, such as locale
  • Allows an application to open windows using the type TYPE_SYSTEM_ALERT, shown on top of all other applications
  • Allows an application to read or write the secure system settings
  • Allows an application to restart other applications
  • Allows applications to change the Wi-Fi connectivity state
  • Allows applications to discover, pair, and connect to bluetooth devices
  • Allows applications to open network sockets
  • Allows applications to read and write the SYNC settings
  • Allows applications to write the APN settings
  • Allows mounting and un-mounting of file systems for removable storage
  • Change the phone state, such as powering it on and off
  • Check the phone's current state
  • Make the phone vibrate
  • Prevent the processor from sleeping or the screen from dimming
  • Read or write to the system settings
  • Start once the device has finished booting
  • Write to external storage devices

When the Trojan is executed, it downloads a file that exploits the Open Handset Alliance Android Privilege Escalation Vulnerability (BID 48238) and uses it to get root access on the device.

Next, the Trojan starts its own service:

It then collects the following phone and geographical information from the device:
  • CID
  • IMEI
  • IMSI
  • LAC
  • MNC
  • Model Number
  • Package name of the malware
  • Release version

Next, the Trojan posts the above information to a remote location. It then waits for a response from the server and the location of an APK file to download and install. The downloaded APK file is a remote administration tool (RAT) for Android devices.

The Trojan may then perform the following actions on the compromised device:
  • Access pay-per-view video
  • Call premium-rate numbers
  • Send SMS messages to premium service numbers
  • Steal further information from the mobile device


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.
You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your device has been affected by this risk.

Install Norton Mobile Security
If you do not already have Norton Mobile Security installed on your device, please download the product from the Android marketplace .

Alternatively, you can navigate to the website from your device and download the product from there by completing the following steps:
  1. Select the 90-Day free download.
  2. Click on the Android icon to begin downloading the product.
  3. Click on Install in order to accept the permissions that are being requested by the program.
  4. Next, click Open and then Agree & Launch.

Note: The first time the product runs, you will be required to enter a code that is displayed on the screen in order to activate the product. Enter the provided code and press Submit .

Run a full system scan
Run a full system scan using Norton Mobile Security to remove this risk from the device. To do this, please perform the following actions:
  1. Navigate to the Anti-Malware tab.
  2. Click Scan Now.

Manual removal
To remove this risk manually, please perform the following actions:
  1. Open the Google Android Menu.
  2. Go to the Settings icon and select Applications.
  3. Next, click Manage.
  4. Select the application and click the Uninstall button.
Writeup By: Cathal Mullaney