ALIASES:

Trojan:Win32/Urelas.C (Microsoft); Trojan.Gen.X (Symantec); Trojan.Win32.Agent.vlfv (Kaspersky); Trojan.Win32.Urelas.a (v) (Sunbelt); Trojan horse Generic30.BOXC (AVG)

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 1,420,800 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 29 May 2013

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%\tmpQA_5\taskmgr.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.)

It creates the following folders:

  • %User Temp%\tmpQA_5

(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.)

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\$$WIND~1.BAT

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\$$Windows$$.bat
  • %User Temp%\TextLog.dat

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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 components

[ Learn More ]
There may be some components 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.
  • %System Root%\Windows.bat
  • %User Temp%\TextLog.dat
Windows.bat
  • %User Temp%\TextLog.dat
    •
  • In the Look In drop-down list, select My Computer then press Enter.
  • Once located, select the file then press SHIFT+DELETE to delete it.
  • Repeat the said steps for all files listed.

    • • For Windows Vista and Windows 7 users:

    1. Click Start>Computer.
    2. In the Search input box, type:
      • %System Root%\Windows.bat
      • %User Temp%\TextLog.dat
    3. Once located, select the file then press SHIFT+DELETE to delete it.
    4. Repeat the said steps for all files listed.
      *Note: Read the following Microsoft page if these steps do not work on Windows 7.

    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.
    • %User Temp%\tmpQA_5

    Step 4

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

    Step 5

    Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

    • %System Root%\WIND~1.BAT


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