Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: Yes

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan drops a component that overwrites disk partitions. It renders the computer unusable after reboot.

It is also used by TROJ_DISTTRACK.C when reporting to its C&C server.

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 282,112 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 18 Nov 2016
Payload: Corrupts hard disk, Modifies files

Arrival Details

This Trojan may be dropped by the following malware:

Installation

This Trojan drops the following component file(s):

  • %System%\Drivers\drdisk.sys

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

NOTES:

The component DRDISK.SYS enables this Trojan to overwrite all disk partitions with a JPEG image file. This renders the system unusable after reboot.

This Trojan overwrites files with the same JPEG image file used for the disk corruption. The files that it overwrites are the following:

  • All files in C:\Documents and Settings containing the words "download" and "document" in the file name.
  • All files in C:\Users containing the following words in the file name:
    • download
    • document
    • picture
    • video
    • music
  • All files in C:\Documents and Settings and C:\Users containing the word "desktop" in the file name.
  • All files in C:\Windows\System32\Drivers.
  • All files in C:\Windows\System32\Config containing the word "systemprofile" in the file name.

It also creates the file %Windows%\inf\netf{4 random characters}.pnf. The said file contains the number of files to be compromised. It is used by TROJ_DISTTRACK.C when reporting to its C&C server.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.906.08
FIRST VSAPI PATTERN DATE: 18 Nov 2016
VSAPI OPR PATTERN File: 12.907.00
VSAPI OPR PATTERN Date: 19 Nov 2016

Step 1

Trend Micro products with the XGen technology detect this malware as

[ Learn More ]
  • TROJ.WIN32.TRX.XXPE0007

Step 2

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

Step 3

Remove the malware/grayware file that dropped/downloaded TROJ_WIPMBR.C. (Note: Please skip this step if the threat(s) listed below have already been removed.)

Step 4

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  %System%\Drivers\drdisk.sys

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_WIPMBR.C. 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.

Step 6

Restore your system's Master Boot Record (MBR)

To restore your system's Master Boot Record (MBR):

• On Windows 2000, XP, and Server 2003:

  1. Insert your Windows Installation CD into your CD drive then restart your computer.
  2. When prompted, press any key to boot from the CD.
  3. On the Main Menu, type r to enter the Recovery Console.
    (Note for Windows 2000: After pressing r, type c to choose the Recovery Console on the repair options screen.)
  4. Type the number that corresponds to the drive and folder that contains Windows (usually C:\WINDOWS) and press Enter.
  5. Type your Administrator password and press Enter.
  6. In the input box, type the following then press Enter:
    fixmbr {affected drive}
  7. Type exit and press Enter to restart the system normally.

• On Windows Vista, 7, and Server 2008:

  1. Insert your Windows Installation DVD into the DVD drive, then press the restart button on your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to choose the installation language. On the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Repair your computer.
  4. Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
  5. If the Startup Repair window appears, click Cancel, Yes, then Finish.
  6. In the System Recovery Options menu, click Command Prompt.
  7. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  8. Type exit and press Enter to close the Command Prompt window.
  9. Click Restart to restart your computer normally.

• On Windows 8, 8.1, and Server 2012:

  1. Insert your Windows Installation DVD in the DVD drive, then restart your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to select the keyboard layout. Then on the Windows Setup window, choose your language, locale, and input method. Click Next, then click Repair your computer.
  4. Click Troubleshoot>Advanced Options>Command Prompt.
  5. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  6. Type exit and press Enter to close the Command Prompt window.
  7. Click Continue to restart the system normally.

Step 7

Restore files from backup Only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on your computer again.


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