ALIASES:

Worm:Win32/Cambot.C (Microsoft); Trojan.Zbot (Symantec); Backdoor.Win32.Androm.ayzd (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

 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.

It disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size: 148,480 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Apr 2015

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:

  • %User Profile%\Microsoft\javaw.exe.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Java Update = "%User Profile%\Microsoft\javaw.exe.exe "

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run
VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\run
VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}.210.181
  • {BLOCKED}1.154.180

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.750

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

Step 4

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    • run
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    • run

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Java Update = "%User Profile%\Microsoft\javaw.exe.exe "
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run
    • VO06ZKYWGGNX = "%User Profile%\Application Data\0D6G6FNC.exe"

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.YUYBS. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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