TROJ_DROPPER.DND

 Modified by: Rhena Inocencio

 ALIASES:

Trojan.Win32.Agent.ahhxo (Kaspersky)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

This Trojan may be downloaded by other malware/grayware from remote sites.

  TECHNICAL DETAILS

File Size:

77,824 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Sep 2014

Payload:

Connects to URLs/IPs, Drops files

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:

  • TROJ_DLOADE.DND

It may be downloaded from the following remote sites:

  • https://dl.dropboxusercontent.com/s/ogp7r55qr1h206h/Flash_Players2.exe

Installation

This Trojan drops the following files:

  • {Malware Path}\wincls.exe - also detected as TROJ_DROPPER.DND
  • %Windows%\flash.exe - also detected as TROJ_DROPPER.DND (copy of wincls.exe)

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

It drops the following component file(s):

  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\crx-to-exe-convert.txt
  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\manifest.json
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\crx-to-exe-convert.txt
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\manifest.json

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It creates the following folders:

  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap
  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Flash Player = "%Windows%\flash.exe"

NOTES:

This Trojan forces close chrome browser by taskkill command.

The dropped component flash.exe installs chrome browser extension by dropping the above-mentioned files.

It connects to the following URL to receive configuration setting for the installed browser extension:

  • http://{BLOCKED}m.net/crx/i.php

The sites accessed by this Trojan may vary depending on the received data from the above-mentioned URL.

The browser extension accesses the following URLs by default:

  • http://{BLOCKED}gnal.com/sincan/user.php
  • http://{BLOCKED}gnal.com/sincan/post.php

The updated browser extension configuration accesses the following URL:

  • http://{BLOCKED}il.com/net/user.php

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.102.03

FIRST VSAPI PATTERN DATE:

22 Aug 2014

VSAPI OPR PATTERN File:

11.103.00

VSAPI OPR PATTERN Date:

23 Aug 2014

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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
    • Flash Player = "%Windows%\flash.exe"

Step 5

Search and delete this file

[ 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 Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\crx-to-exe-convert.txt
  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\manifest.json
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\crx-to-exe-convert.txt
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0\manifest.json

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0
  • %System Root%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap\1.0_0
  • %AppDataLocal%\Google\Chrome\User Data\Default\Extensions\mneihfalhphgjcdkangphoiddpcbmhap

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DROPPER.DND. 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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