ALIASES:

Trojan:Win32/Ropest.F (Microsoft)

 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, 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 executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 459,866 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Oct 2014
Payload: Drops files, Collects system information

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:

    It creates the following folders:

    • %Application Data%\Microsoft\Windows\IEUpdate

    (Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

    Other System Modifications

    This Trojan modifies the following registry entries:

    HKEY_CURRENT_USER\Software\Microsoft\
    Windows\CurrentVersion\Explorer\
    Advanced
    Hidden = "2"

    (Note: The default value data of the said registry entry is {user-defined}.)

    HKEY_CURRENT_USER\Software\Microsoft\
    Windows\CurrentVersion\Explorer\
    Advanced
    ShowSuperHidden = "0"

    (Note: The default value data of the said registry entry is 1.)

    Dropping Routine

    This Trojan drops the following files:

    • %Application Data%\Microsoft\Windows\IEUpdate\iexpress.exe
    • %User Startup%\iexpress.lnk - automatically executes the dropped iexpress.exe

    (Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

    It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

    Information Theft

    This Trojan gathers the following data:

    • OS Version
    • System Information

    Other Details

    This Trojan does the following:

    • It connects to the following IP to send system information:
      {BLOCKED}.{BLOCKED}.141.15
      posts the following information:
      • "hi"
        "123|{OS Version}|1|{System Info}|1|511"
    • It executes the following command in CMD:
      cmd.exe /c ping 127.0.0.1

    It deletes the initially executed copy of itself

      SOLUTION

    Minimum Scan Engine: 9.700
    FIRST VSAPI PATTERN FILE: 11.216.08
    FIRST VSAPI PATTERN DATE: 17 Oct 2014
    VSAPI OPR PATTERN File: 11.217.00
    VSAPI OPR PATTERN Date: 17 Oct 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

    Restart in Safe Mode

    [ Learn More ]

    Step 3

    Restore this modified registry value

    [ Learn More ]

    Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
      • From: Hidden = "2"
        To: Hidden = "{user-defined}"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
      • From: ShowSuperHidden = "0"
        To: ShowSuperHidden = "1"

    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 Startup%\iexpress.lnk
    • %Application Data%\Microsoft\Windows\IEUpdate\iexpress.exe

    Step 5

    Search and delete these folders

    [ 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.
    • %Application Data%\Microsoft\Windows\IEUpdate

    Step 6

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ROPEST.UHU. 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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