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TROJ_WIPMBR.A
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
In the wild: Yes

Overview


Infection Channel: Dropped by other malware

This Trojan overwrites disk partitions, rendering the affected computer unusable and unrecoverable.

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

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

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

This Trojan may be dropped by other malware.

Technical Details


File size: 194,048 bytes
File type: EXE
Memory resident: Yes
Initial samples received date: 15 Aug 2012

Arrival Details

This Trojan may be dropped by the following malware:

  • WORM_DISTTRACK.A

Installation

This Trojan drops the following files:

  • {malware path}\f1.inf
  • {malware path}\f2.inf

It drops the following non-malicious files:

  • %System%\Drivers\drdisk.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

NOTES:

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

The dropped file F1.INF is a text file that contains the full path names of 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
  • f1.inf
  • f2.inf

The dropped file F2.INF is a text file contains the full path names of the following:

  • 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

This Trojan overwrites the files listed in F1.INF and F2.INF with the same damaged JPEG image used that causes disk corruption.

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.A when reporting to its C&C server.

Solution


Minimum scan engine: 9.200
VSAPI OPR Pattern Version: 9.331.00
VSAPI OPR Pattern Release Date: 17 Aug 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware/grayware files that dropped/downloaded TROJ_WIPMBR.A

Step 3

Identify files detected as TROJ_WIPMBR.A, then restore the Master Boot Record and delete malware files using Recovery Console

[ Learn more ]

Step 4

Search and delete this file

[ Learn more ]
There may be some component 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.A. 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 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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Analysis By: Christopher Daniel So

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