TROJ_DLOADER.FRO

July 06, 2013
 ALIASES:

Adware:Win32/DuDuAccelerator, TrojanDownloader:Win32/AF, Spyware:Win32/CnsMin, Spyware:Win32/CnsMin, (Microsoft); [340.nsis\0000a000.EXE\0000a000.EXE]:QLowZones-4, [341.nsis]:Generic MultiDropper.d (McAfee); ARC:NSIS, PAK:[data0038]:UPX, PAK:[data0044]:UPX, ARC:[data0057]:CHM, ARC:[data0334]:CHM, ARC:[data0 (Kaspersky); DuDuAccelerator, Trojan-Downloader.AF, 3721 Chinese Keywords (CNSMin), 3721 Chinese Keywords (CNSMin (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

3,427,609 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

16 Nov 2011

Arrival Details

This Trojan 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 Trojan creates the following folders:

  • %User Temp%\nsi3.tmp

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

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\nsn1.tmp
  • %User Temp%\nsi3.tmp

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

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\nsd2.tmp
  • %User Temp%\nsi3.tmp\ioSpecial.ini
  • %User Temp%\nsi3.tmp\modern-wizard.bmp
  • %User Temp%\nsi3.tmp\modern-header.bmp
  • %User Temp%\nsi3.tmp\InstallOptions.dll

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

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Search and delete this folder

[ 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. %User Temp%\nsi3.tmp

Step 3

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\nsd2.tmp
  • %User Temp%\nsi3.tmp\ioSpecial.ini
  • %User Temp%\nsi3.tmp\modern-wizard.bmp
  • %User Temp%\nsi3.tmp\modern-header.bmp
  • %User Temp%\nsi3.tmp\InstallOptions.dll

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADER.FRO. 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 5

Restore this file 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 you computer again.

  • %User Temp%\nsn1.tmp
  • %User Temp%\nsi3.tmp


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