ALIASES:

TrojanDownloader:Win32/Potentialdownloader.A (Microsoft); Virus.Win32.CrazyPrier.a (Kaspersky); TrojanDownloader.Win32.PotentialDownloader.a (v) (Sunbelt); Gen:Variant.Buzy.3169 (FSecure)

 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: 258,048 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 26 Jul 2012

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:

  • {malware path and file name}\cache

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\DNFUpdate0308.exe
  • {malware path and file name}\cache\update.dat

(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.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://home.{BLOCKED}1.com/5759497/diary/item/100{BLOCKED}1553.html
  • http://home.{BLOCKED}1.com/5759497/diary/item/100{BLOCKED}1552.html
  • http://www.{BLOCKED}k.cn/ContentPane.aspx?{random characters}
  • http://update.{BLOCKED}2.cn/product/update.ini
  • http://update.{BLOCKED}ervice.net/product/update.ini

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

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

Search and delete these files

[ 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.
  • %User Temp%\DNFUpdate0308.exe
  • {malware path and file name}\cache\update.dat

Step 3

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.
  • {malware path and file name}\cache

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_PAM_0000030785.T3. 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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