TROJ_ROPEST.WRX

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

Trojan.Ransom.ED (Malwarebytes)

 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

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 modifies the Internet Explorer Zone Settings. It lowers the security setting of Internet Explorer.

It connects to certain websites to send and receive information. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

375,372 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

21 Nov 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 and executes them:

  • %User Temp%\tmp{random number}.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:

  • %System Root%\Recycler\{User SID}\$ast-{User SID}\{random characters}.dat
  • %Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe - detected as TROJ_ROPEST.SM

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %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.)

It creates the following folders with attributes set to System and Hidden to prevent users from discovering and removing its components:

  • %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.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Control Panel\Desktop
SCRNSAVE.EXE = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Command Processor
AutoRun = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
Run = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random name} = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{random name} = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"

It drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • %Start Menu%\Programs\Startup\{random name}.lnk

(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{GUID}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{GUID}\Enum

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{GUID}
{random characters} = {hex values}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\Feature Control\
FEATURE_BROWSER_EMULATION
{random name}.exe = "1f40"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\Feature Control\
FEATURE_GPU_RENDERING
{random name}.exe = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
{random characters} = {hex values}

It modifies the following registry entries to hide files with Hidden attributes:

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

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

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

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

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

It lowers the security setting of Internet Explorer.

Other Details

This Trojan connects to the following website to send and receive information:

  • http://{BLOCKED}.{BLOCKED}4.2.20:8080/pgt/?ver={malware version}&id={malware id}&r={date & time}&os={Operating system, mshtml.dll version}&res={RAM (memory usage) and processor information}
  • http://{BLOCKED}5.{BLOCKED}.141.72:8080/pgt/?ver={malware version}&id={malware id}&r={date & time}&os={Operating system, mshtml.dll version}&res={RAM (memory usage) and processor information}
  • http://{BLOCKED}5.{BLOCKED}.141.146:8080/pgt/?ver={malware version}&id={malware id}&r={date & time}&os={Operating system, mshtml.dll version}&res={RAM (memory usage) and processor information}

It sets the attributes of the following file(s) to Hidden and System:

  • %Application Data%\Microsoft\Windows\IEUpdate\{random name}.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.)

It does the following:

  • Perform click-fraud
  • Lock screen (see Notes for details)
  • Send system information
  • Update Adobe Flash Player

It deletes the initially executed copy of itself

NOTES:

Where {random name} can be any file name from the %System% (usually C:\Windows\system32) folder except for file name with the following strings:

  • update
  • setup
  • install

The lock screen displays the following message:

Windows locked! Your ID is 0x{hex number}. Send 250 WMZ to Z268598233219 and follow instructions.

  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

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

Restart in Safe Mode

[ Learn More ]

Step 4

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

     
    • TROJ_ROPEST.SM

Step 5

Delete this registry key

[ 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\Discardable\PostSetup\Component Categories
    • {GUID}
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup
    • 30002
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories
    • {GUID}
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup
    • 30002

Step 6

Delete this 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\Control Panel\Desktop
    • SCRNSAVE.EXE = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Command Processor
    • AutoRun = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • Run = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random name} = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • {random name} = "%Application Data%\Microsoft\Windows\IEUpdate\{random name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Feature Control\FEATURE_BROWSER_EMULATION
    • {random name}.exe = "1f40"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Feature Control\FEATURE_GPU_RENDERING
    • {random name}.exe = "1"

Step 7

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 = "0"
      To: Hidden = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = "0"
      To: ShowSuperHidden = "1"

Step 8

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
  • %System Root%\Recycler\{User SID}\$ast-{User SID}\{random characters}.dat

Step 9

Search and delete this file

[ 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.
  • %Start Menu%\Programs\Startup\{random name}.lnk

Step 10

Reset Internet security settings

[ Learn More ]

Step 11

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