PUA.Win32.SlimWare.CH

May 16, 2022
 Analysis by: Khristian Joseph Morales
 ALIASES:

Riskware/Slimware (FORTINET)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

999,320 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 May 2022

Payload:

Connects to URLs/IPs, Drops files, Modifies system registry, Schedules tasks

Arrival Details

This Potentially Unwanted Application 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 Potentially Unwanted Application adds the following folders:

  • %AppDataLocal%\slimware utilities inc (Contains settings and configuration files)
  • %Program Files%\slimware utilities (Contains installed application and components)
  • %Program Files%\driverupdate (Contains installed application and components)

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops the following files:

  • %User Temp%\{random characters}.tmp
  • %User Temp%\{random characters}.tmp.msi
  • %User Temp%\{random characters}.tmp.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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • %Program Files%\DriverUpdate\DriverUpdate.exe -installscan
  • %User Temp%\scp250F.tmp.exe SI_LAUNCH=onreboot SI_MODE=toaster SI_DELAY=5 @P2_ORIGIN={random characters}@P2={random characters}@UL_STUBID={stub id}
  • %Program Files%\Internet Explorer\iexplore.exe "http://www.{BLOCKED}update.net/scan_results/index.php?lang=en&installer_data={encoded information}&machineId={machine id}&installId={install id}"

Autostart Technique

This Potentially Unwanted Application starts the following services:

  • Name : SlimWareServices
    Image path: %Program Files%\slimware utilities\services\slimware.services.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Potentially Unwanted Application adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
DriverUpdate = "%Program Files%\DriverUpdate\DriverUpdate.exe" -boot

Download Routine

This Potentially Unwanted Application connects to the following URL(s) to download its component file(s):

  • http://apps-api.{BLOCKED}reutilities.com/install/du/{OS Version}/x86/DriverUpdate-setup.msi.bz2?machineId={machine id}
  • http://cdn.{BLOCKED}eaner.com/downloads/scplus/SlimCleanerPlus_en-US_x86_Silent.exe

Other Details

This Potentially Unwanted Application adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\SlimWare Utilities Inc (Contains configuration and information of installed application)

HKEY_CURRENT_USER\Software\SlimWare Utilities Inc (Contains configuration and information of installed application)

It does the following:

  • It connects to the following URL to send and receive information regarding installation:
    • http://trk.{BLOCKED}reutilities.com/ulc.php?ev={Installer Event}&upl={encoded information}&machineId={machine id}&platformOS={Operating System}&platformOSVersion={OS Version}&installer={installer}&installerVersion={installer version}&product={product version}&msBclVersion={Bcl Version}
    • http://trk.{BLOCKED}reutilities.com/ulc.php?ev={Installer Event}&upl={encoded information}&machineId={machine id}&platformOS={Operating System}&platformOSVersion={OS Version}&installer={installer}&installerVersion={installer version}&product={product version}&installId={install id}&description={description}&result={result}
    • http://trk.{BLOCKED}reutilities.com/ulc.php?ev={Installer Event}&upl={encoded information}&machineId={machine id}&platformOS={Operating System}&platformOSVersion={OS Version}&installer={installer}&installerVersion={installer version}&product={product version}&installId={install id}&errorType={Operating System}DesktopError&errorCode={error code}&page=app-side-error&action={action}
    • https://stc.{BLOCKED}reutilities.com/gettrack?product={product}&p2={random characters}&secondOfferOrigin={random characters}&ul_stubid={stub id}
    • http://trk.{BLOCKED}reutilities.com/ulc.php?ev={Installer Event}&platformOSVersion={OS Version}&secondOfferOrigin={random characters}&ul_stubid={stub id}&p2={random characters}&installer={installer}&product={product}&installerVersion={installer version}&machineId={machine id}&platformOS={Operating System}
    • https://{BLOCKED}re.com/register/driverupdate?lang=en&{Installer Event}={encoded information}&machineId={machine id}&installId={install id}
    • http://{BLOCKED}re.com/purchase/driverupdate?lang=en&{Installer Event}={encoded information}&machineId={machine id}&installId={install id}
    • https://{BLOCKED}re.com/purchase/driverupdate?lang=en&{Installer Event}={encoded information}&machineId={machine id}&installId={install id}
    • http://{BLOCKED}re.com/driverupdate?lang=en&{Installer Event}={encoded information}&machineId={machine id}&installId={install id}
    • https://{BLOCKED}re.com/driverupdate?lang=en&{Installer Event}={encoded information}&machineId={machine id}&installId={install id}
    • http://apps-api.{BLOCKED}reutilities.com/
  • It sends the following information regarding installation:
    • Installer event
    • Default browser information (e.g. browser name, browser language)
    • Operating system information (e.g. name, version)

It adds the following scheduled tasks:

  • Task Name: DriverUpdate
    Task to run: %Program Files%\driverupdate\driverupdate.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine:

9.800

SSAPI PATTERN File:

2.513.00

SSAPI PATTERN Date:

12 May 2022

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • TROJ.Win32.TRX.XXPE50FFF055

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

Disable this malware service

[ Learn More ]
    • SlimWareServices
DATA_GENERIC
  • Press Enter. A message should indicate that the service has been stopped successfully.
  • Close the command prompt window.

    • Step 6

    Deleting Scheduled Tasks

    The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

    • Task name: DriverUpdate
    • Task to be run: %Program Files%\driverupdate\driverupdate.exe

    For Windows 2000, Windows XP, and Windows Server 2003:

    1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
      System Tools>Scheduled Tasks.
    2. Locate each {Task Name} values listed above in the Name column.
    3. Right-click on the said file(s) with the aforementioned value.
    4. Click on Properties. In the Run field, check for the listed {Task to be run}.
    5. If the strings match the list above, delete the task.

    For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

    1. Open the Windows Task Scheduler. To do this:
      • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
      • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
    2. In the left panel, click Task Scheduler Library.
    3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
    4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
    5. If the said string is found, delete the task.

    Step 7

    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\Software\Microsoft\Windows\CurrentVersion\Run
      • DriverUpdate = "%Program Files%\DriverUpdate\DriverUpdate.exe" -boot

    Step 8

    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.

    • HKEY_LOCAL_MACHINE\SOFTWARE\SlimWare Utilities Inc
    • HKEY_CURRENT_USER\Software\SlimWare Utilities Inc

    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.
    • %User Temp%\{Random characters}.tmp
    • %User Temp%\{Random characters}.tmp.msi
    • %User Temp%\{Random characters}.tmp.exe

    Step 10

    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.  
    • %AppDataLocal%\slimware utilities inc
    • %Program Files%\slimware utilities
    • %Program Files%\driverupdate

    Step 11

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as PUA.Win32.SlimWare.CH. 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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