Threat Explorer

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PUA.Linkular

PUA.Linkular

Updated:
June 23, 2015
Risk Impact:
Low
Systems Affected:
Windows

Behavior

PUA.Linkular is a potentially unwanted application that may download additional software on the computer.

Note: Virus definitions dated June 23, 2015 or earlier detect this threat as Linkular.

Antivirus Protection Dates

  • Initial Rapid Release version October 02, 2014 revision 022
  • Latest Rapid Release version November 19, 2017 revision 034
  • Initial Daily Certified version September 22, 2014 revision 018
  • Latest Daily Certified version November 20, 2017 revision 001
  • Initial Weekly Certified release date September 24, 2014
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.
Linkular is a application downloader and installer bundled with third party software.

The program installs well-known clean applications but also installs additional software along with the main application.

The application creates the following processes:
  • %Temp%\nsf30.tmp\ef.exe
  • %Temp%\nsf30.tmp\mf.exe
  • %Temp%\nsf30.tmp\ns31.tmp
  • %Temp%\nsf30.tmp\ns32.tmp

The application creates the following files:
  • %Temp%\nsf30.tmp\BaseConvert.dll
  • %Temp%\nsf30.tmp\Dialer.dll
  • %Temp%\nsf30.tmp\dummy.htm
  • %Temp%\nsf30.tmp\dummyres
  • %Temp%\nsf30.tmp\GetVersion.dll
  • %Temp%\nsf30.tmp\icons\1.ico
  • %Temp%\nsf30.tmp\icons\10.ico
  • %Temp%\nsf30.tmp\icons\100.ico
  • %Temp%\nsf30.tmp\icons\10000.ico
  • %Temp%\nsf30.tmp\inetc.dll
  • %Temp%\nsf30.tmp\inetc.dll.out0
  • %Temp%\nsf30.tmp\inetc.dll.out1
  • %Temp%\nsf30.tmp\main.ico
  • %Temp%\nsf30.tmp\Math.dll
  • %Temp%\nsf30.tmp\nsExec.dll
  • %Temp%\nsf30.tmp\nsisunz.dll
  • %Temp%\nsf30.tmp\SimpleInstaller.exe
  • %Temp%\nsf30.tmp\System.dll

The application creates the following registry entries:
  • HKEY_CURRENT_USER\Software\PowerPack\"guid" = "d7d4376449e94605b7e48e5a540f78d"
  • HKEY_CURRENT_USER\Software\PowerPack\714\"t" = "[DATE AND TIME]"

When the application is executed, it offers to install other applications as a bundle and displays the following window:



Note: The application does not display the name of the bundled applications that it offers to install.

The application connects to the following remote location in order to retrieve a list of bundled applications to install:
  • www.powerpackdl.com

The application offers two modes of installation, quick and custom. Custom allows the user to deselect the bundled software but both options will install additional applications along with the main application.

The application displays a EULA which is quickly replaced with a window requesting that the user continue the installation. If the user clicks OK, the installation begins in quick mode and installs the bundled applications.



The application displays a window with the title of the clean application while installing the bundled applications:



You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your computer has been affected by this risk.

Before proceeding further we recommend that you run a full system scan . If that does not resolve the problem you can try one of the options available below.



FOR NORTON USERS
If you are a Norton product user, we recommend you try the following resources to remove this risk.


Removal Tool

If you have an infected Windows system file, you may need to replace it using the Windows installation CD .


How to reduce the risk of infection
The following resources provide further information and best practices to help reduce the risk of infection.


FOR BUSINESS USERS
If you are a Symantec business product user, we recommend you try the following resources to remove this risk.


Identifying and submitting suspect files
Submitting suspicious files to Symantec allows us to ensure that our protection capabilities keep up with the ever-changing threat landscape. Submitted files are analyzed by Symantec Security Response and, where necessary, updated definitions are immediately distributed through LiveUpdate™ to all Symantec end points. This ensures that other computers nearby are protected from attack. The following resources may help in identifying suspicious files for submission to Symantec.


Removal Tool

If you have an infected Windows system file, you may need to replace it using the Windows installation CD .


How to reduce the risk of infection
The following resource provides further information and best practices to help reduce the risk of infection.
Protecting your business network



MANUAL REMOVAL
The following instructions pertain to all current Symantec antivirus products.


1. Performing a full system scan
How to run a full system scan using your Symantec product


2. Restoring settings in the registry
Many risks make modifications to the registry, which could impact the functionality or performance of the compromised computer. While many of these modifications can be restored through various Windows components, it may be necessary to edit the registry. See in the Technical Details of this writeup for information about which registry keys were created or modified. Delete registry subkeys and entries created by the risk and return all modified registry entries to their previous values.