Analysis by: John Donnie Celestre
ALIASES:

Adware/Agent, Adware/Agent (FORTINET), HEUR:AdWare.Win32.Agent.gen (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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.

It attempts to access certain websites. However, the websites are inaccessible as of this writing.

  TECHNICAL DETAILS

File Size: 381,416 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 20 Aug 2018
Payload: Connects to URLs/IPs

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 drops the following files:

  • %AppDataLocal%\PConverterTooltab\TooltabExtension.dll

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista, 7, and 8.)

Other System Modifications

This Potentially Unwanted Application adds the following registry keys:

HKEY_CURRENT_USER\Software\PConverter

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer

It adds the following registry entries:

HKEY_CURRENT_USER\Software\PConverter
Start Page = http://hp.myway.com/pconverter/LMFRFR/index.html?{string}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer
DisplayName = PConverter Internet Explorer Homepage and New Tab

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer
UninstallString = Rundll32.exe "%AppDataLocal%\PConverterTooltab\TooltabExtension.dll" U uninstall:PConverter

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer
Publisher = Mindspark Interactive Network, Inc.

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer
HelpLink = http://support.mindspark.com/

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
PConverterTooltab Uninstall Internet Explorer
URLInfoAbout = http://support.mindspark.com/

HKEY_CURRENT_USER\Software\PConverter
UnInstallSurveyUrl = http://www.research.net/r/HYSCVNM?{string}

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = http://hp.myway.com/pconverter/LMFRFR/index.html?{string}

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

Adware Routine

This Potentially Unwanted Application connects to the following URL(s) to display ads on the affected system:

  • http://anx.mindspark.com/anx.gif?{string}

Other Details

This Potentially Unwanted Application attempts to access certain websites. However, the websites are inaccessible as of this writing.

It connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.197.200:80 (United States)
  • {BLOCKED.{BLOCKED}.135.9:80 (United States)
  • {BLOCKED}.{BLOCKED}.28.251:443 (United States)
  • {BLOCKED}.{BLOCKED}.233.64:443 (United States)
  • {BLOCKED}.{BLOCKED}.135.11:80 (United States)
  • {BLOCKED}.{BLOCKED}.237.29:80 (Asia/Pacific Region)
  • {BLOCKED}.{BLOCKED}.233.64:80 (United States)

It does the following:

  • It displays the following upon installation:

  • Sets browser homepage as follows:

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 1.993.00
SSAPI PATTERN Date: 23 Aug 2018

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

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CURRENT_USER\Software
    • PConverter
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
    • PConverterTooltab Uninstall Internet Explorer

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Start Page = {user preference}

Step 5

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.
  • %AppDataLocal%\PConverterTooltab\TooltabExtension.dll

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA_PCONVERTER.GA. 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 the following Trend Micro Support pages for more information:

NOTES:

Enter the following in command prompt before deleting the dropped file:

Rundll32.exe "%AppDataLocal%\PConverterTooltab\TooltabExtension.dll" U uninstall:PConverter


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