Analysis by: Rika Joi Gregorio
ALIASES:

TrojanDownloader:Win32/Upatre.A(Microsoft),Trojan-Downloader.Win32.Small.cvpr(Kaspersky),PWS-Zbot.gen.ad(McAfee)

 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: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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.

It does not have any propagation routine.

It does not have any backdoor routine.

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

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 22,528 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 27 Aug 2013
Payload: Downloads files

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

  • %User Temp%\jcbnaf.exe - it deletes the original copy

(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.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan accesses the following websites to download files:

  • {BLOCKED}.165.222:443/bomberman.exe

It saves the files it downloads using the following names:

  • %User Temp%\bgnddkje.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.)

Trend Micro detects the dowloaded file as:

  • TSPY_ZBOT.SMR9

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

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.242.01
FIRST VSAPI PATTERN DATE: 27 Aug 2013
VSAPI OPR PATTERN File: 10.243.00
VSAPI OPR PATTERN Date: 28 Aug 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 the malware/grayware file dropped/downloaded by TROJ_DLOADR.BTA

  • TSPY_ZBOT.SMR9

Step 3

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