Analysis by: RonJay Kristoffer Caragay
ALIASES:

Trojan:Win32/WipMBR.gen!A (Microsoft); DistTrack!comm (McAfee); Trojan.Win32.EraseMBR.a (Kaspersky); Win32/DistTrack.A (ESET-NOD32); W32/EraseMBR.A!tr (Fortinet); W32.Disttrack (Symantec); Troj/DisTrack-A (Sophos)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan is responsible for sending information about the infection back to its server.

This worm may be dropped by other malware.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 16 Aug 2012
Payload: Connects to URLs/IPs

Arrival Details

This worm may be dropped by the following malware:

  • WORM_DISTTRACK.A

Download Routine

This worm saves the files it downloads using the following names:

  • %Windows%\inf\netft429.pnf
  • %Temp%\filer{random}.exe ← deletes if already existing

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

Other Details

This worm connects to the following website to send and receive information:

  • http://{BLOCKED}.{BLOCKED}.252.19/ajax_modal/modal/data.asp?mydata={FILES}&uid={IP Address}&state={INFECTION ID}
  • http://{BLOCKED}e/ajax_modal/modal/data.asp?mydata={FILES}&uid={IP Address}&state={INFECTION ID}
    Where {FILES} is the number of files infected by the malware. This is taken from the file %Windows%\inf\netfb318.pnf which is created by the wiper component TROJ_WIPMBR.A.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 13.178.02
FIRST VSAPI PATTERN DATE: 24 Jan 2017
VSAPI OPR PATTERN File: 13.179.00
VSAPI OPR PATTERN Date: 25 Jan 2017

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

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

Step 3

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.  
  • %Windows%\inf\netft429.pnf
  • %Temp%\filer{random}.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as WORM_DISTTRACK.SMB. 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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