TROJ_UPATRE.YYLW

June 14, 2014
 Analysis by: Al Victor de Leon
 ALIASES:

TrojanDownloader:Win32/Upatre.AA (Microsoft), Win32/TrojanDownloader.Waski.E trojan (Nod32), Trojan.Gen.2 (Symantec), Win32.Malware!Drop (Sunbelt), W32/Kryptik.CCXH!tr (Fortinet),

 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

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 deletes itself after execution.

  TECHNICAL DETAILS

File Size:

34,816 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

03 Jun 2014

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:

  • %User Temp%\jeovhy.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 saves the files it downloads using the following names:

  • %User Temp%\ohfla.exe
  • %Temporary Internet Files%\Content.IE5\{folder name}\2705USmw[1].opt

(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.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}singh.com/images/2705USmw.opt

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.700

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 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%\ohfla.exe

Step 3

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

NOTES:

To delete the file %Temporary Internet Files%\Content.IE5\{folder name}\2705USmw[1].opt:

Go to Start > Search.

Click All files and folders and input the following information:

All or part of the file name: 2705USmw[1].opt

Look in: %Temporary Internet Files%\Content.IE5

Once located, select the file then press SHIFT+DELETE to permanently delete the file.


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