BKDR_ANDROM.DZZ

February 23, 2013
 Analysis by: Jaime Benigno Reyes
 ALIASES:

Worm:Win32/Gamarue.I (Microsoft), Trojan-Ransom.Win32.PornoAsset.bxjs (Kaspersky), Trojan-FAZJ!2F5CA196C31F (McAfee)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

64,000 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

21 Feb 2013

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor drops the following copies of itself into the affected system:

  • %ProgramData%\svchost.exe (Windows Vista and 7 only)
  • %System Root%\Users\All Users\svchost.exe (Windows Vista and 7 only)
  • %System Root%\Documents and Settings\All Users\svchost.exe (versions other than Windows Vista and 7)

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%ProgramData%\svchost.exe" (Windows Vista and 7 only and if Java update is disabled in startup)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%System Root%\Documents and Settings\All Users\svchost.exe" (versions other than Windows Vista and 7 and if Java update is disabled in startup)

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%ProgramData%\svchost.exe" (Windows Vista and 7 only and if Java update is enabled in startup)

(Note: The default value data of the said registry entry is "{Java Installation Folder}\jusched.exe".)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%System Root%\Documents and Settings\All Users\svchost.exe" (versions other than Windows Vista and 7 and if Java update is enabled in startup)

(Note: The default value data of the said registry entry is "{Java Installation Folder}\jusched.exe".)