Analysis by: Anthony Joe Melgarejo
 Modified by: Alvin Bacani

ALIASES:

TrojanDownloader:Win32/Upatre.A (Microsoft)

 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: Spammed via email

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 34,816 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Dec 2013
Payload: Downloads files, Connects to URLs/IPs

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\budha.exe

(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.)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • https://{BLOCKED}dasia.com/logos/astore.exe
  • https://{BLOCKED}gfloorrestoration.com/source/logo.exe
  • https://{BLOCKED}online.net/images/banner.exe
  • https://{BLOCKED}ndjoin.in/wp-content/uploads/2011/11/photography4.exe
  • https://{BLOCKED}ngtank.com/images/slade1.exe
  • https://{BLOCKED}erforex.com/images/trade.exe

It saves the files it downloads using the following names:

  • %User Temp%\kilf.exe - detected as TSPY_ZBOT.VZA
  • %Temporary Internet Files%\Content.IE5\{folder name}\logo[{number}].exe - detected as TSPY_ZBOT.VZA
  • %Temporary Internet Files%\Content.IE5\{folder name}\astore[{number}].exe - detected as TSPY_ZBOT.VZA

(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.. %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

It saves the file it downloads in a path where {folder name} is one of the folders found in %Temporary Internet Files%\Content.IE5 folder with 8 alphanumeric characters.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.396.05
FIRST VSAPI PATTERN DATE: 07 Nov 2013
VSAPI OPR PATTERN File: 10.397.00
VSAPI OPR PATTERN Date: 07 Nov 2013

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 malware/grayware files dropped/downloaded by TROJ_UPATRE.SMB

     
    • TSPY_ZBOT.VZA

Step 3

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