Analysis by: Michelle Morales
 Modified by: Francis Xavier Antazo
ALIASES:

Win32/TrojanDownloader.Waski.F trojan (NOD32)

 PLATFORM:

Windows

 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, Via email

This Trojan arrives as attachment to mass-mailed email messages. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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: 24 Dec 2014
Payload: Connects to URLs/IPs

Arrival Details

This Trojan arrives as attachment to mass-mailed email messages.

It 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%\mvbzo.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 drops the following files:

  • %User Temp%\utt8C0C.tmp - log containing malware path and filename

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}uits.com/pl/up12.soa
  • http://{BLOCKED}ori.org/wp-includes/fonts/up12.soa

It saves the files it downloads using the following names:

  • %User Temp%\EXE1.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 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:

This Trojan accesses the following URLs to send information:

  • http://{BLOCKED}.{BLOCKED}.35.133:{random 5 numbers}/2312us12/{computername}/0/{OS Version}-{Service Pack}/0/
  • http://{BLOCKED}.{BLOCKED}.35.133:{random 5 numbers}/2312us12/{computername}/1/0/0/

The following information are posted:

  • Computer name
  • Operating system version
  • Service pack installed

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.364.09
FIRST VSAPI PATTERN DATE: 23 Dec 2014
VSAPI OPR PATTERN File: 11.365.00
VSAPI OPR PATTERN Date: 24 Dec 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

Remove malware/grayware files dropped/downloaded by TROJ_UPATRE.YYRO. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • TSPY_DYRE.VVPX

Step 4

Search and delete these files

[ 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.
  • %User Temp%\utt8C0C.tmp

Step 5

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