Trojan.Yontoo

Posted: March 22, 2013

Threat Metric

The Threat Meter is a malware assessment that SpywareRemove.com's research team is able to give every identifiable malware threat. Our Threat Meter includes several criteria based off of specific malware threats to value their severity, reach and volume. The Threat Meter is able to give you a numerical breakdown of each threat's initial Threat Level, Detection Count, Volume Count, Trend Path and Percentage Impact. The overall ranking of each threat in the Threat Meter is a basic breakdown of how all threats are ranked within our own extensive malware database. The scoring for each specific malware threat can be easily compared to other emerging threats to draw a contrast in its particular severity. The Threat Meter is a useful tool in the endeavor of seeking a solution to remove a threat or pursue additional analytical research for all types of computer users.

The following fields listed on the Threat Meter containing a specific value, are explained in detail below:

Threat Level: The threat level scale goes from 1 to 10 where 10 is the highest level of severity and 1 is the lowest level of severity. Each specific level is relative to the threat's consistent assessed behaviors collected from SpyHunter's risk assessment model.

Detection Count: The collective number of confirmed and suspected cases of a particular malware threat. The detection count is calculated from infected PCs retrieved from diagnostic and scan log reports generated by SpyHunter.

Volume Count: Similar to the detection count, the Volume Count is specifically based on the number of confirmed and suspected threats infecting systems on a daily basis. High volume counts usually represent a popular threat but may or may not have infected a large number of systems. High detection count threats could lay dormant and have a low volume count. Criteria for Volume Count is relative to a daily detection count.

Trend Path: The Trend Path, utilizing an up arrow, down arrow or equal symbol, represents the level of recent movement of a particular threat. Up arrows represent an increase, down arrows represent a decline and the equal symbol represent no change to a threat's recent movement.

% Impact (Last 7 Days): This demonstrates a 7-day period change in the frequency of a malware threat infecting PCs. The percentage impact correlates directly to the current Trend Path to determine a rise or decline in the percentage.

Threat Level:	9/10
Infected PCs:	44

First Seen:	March 22, 2013
Last Seen:	November 25, 2020
OS(es) Affected:	Windows

Also known as Yontoo Adware, Trojan.Yontoo is an upgraded variant of that same PC threat, with additional functions of a malicious nature that are of particular concern for Mac OS X and Windows users. Armed with a new-found compatibility for Mac, Trojan.Yontoo continues the same attacks that Trojan.Yontoo used against Windows PCs in the previous year: by constantly monitoring your online activities and injecting advertisements into various websites without your permission. Trojan.Yontoo also has been caught using disingenuous methods of installing itself that are common for malware, such as claiming to be an update for a media player, and should be considered a malicious, albeit low-level PC threat. SpywareRemove.com malware researchers still encourage removing Trojan.Yontoo with the right anti-malware products, and, as a general precaution, don't recommend that you have any extended contact with advertisements from Trojan.Yontoo's various advertisement rings.

When a Web Page Isn't the Only Thing You're Seeing on Your Browser

Trojan.Yontoo has been in existence for a significant amount of time, but many PC security companies only identified Trojan.Yontoo as a Trojan-level PC threat since recent updates to Yontoo. Trojan.Yontoo's latest version includes cross-platform compatibility with both Mac-based operating systems and Windows and allows Trojan.Yontoo's basic advertising functions to affect all types of Web browsers on the infected PCs. This is particularly notable because Trojan.Yontoo's recent Mac campaigns have distributed Trojan.Yontoo widely enough to make Trojan.Yontoo one of the most widespread adware-based Trojans on that OS.

SpywareRemove.com malware experts haven't noticed any new changes in the Trojan.Yontoo's major attacks, which are designed to display advertisements that are related to sites that you browse. Because the Trojan.Yontoo launches automatically and uses up your PC's system resources to monitor your online web-browsing habits, you also may experience some minor system issues that stem from Trojan.Yontoo's theft of your bandwidth, RAM and other resources. Trojan.Yontoo's advertisements are derived from a wide range of different advertisement rings that pay for the victimized traffic that Trojan.Yontoo creates, and may, in some cases, contain malicious content.

Why the Search for the Latest Movie Gets You a Trojan.Yontoo Infection

Trojan.Yontoo's infection vectors are treading the well-worn path of fake application installers for entertainment, such as movie players, music players, download managers and related codecs. SpywareRemove.com malware research team warns that, besides being installed from general freeware sites, Trojan.Yontoo also has been found to be distributed via websites that are designed specifically to look like media-downloading pages for popular entertainment products. Since these attacks require that you install the fake updates and applications intentionally, the best protection against a Trojan.Yontoo infection is always to install your software from reputable websites.

Because Trojan.Yontoo includes a range of components that are not easily uninstalled by the usual methods, SpywareRemove.com malware researchers also heartily encourage the usage of appropriate anti-malware products for removing Trojan.Yontoo. Some anti-malware programs may be able to detect Trojan.Yontoo based on its previous versions, but others may require updates to their threat databases before they can find and delete Trojan.Yontoo.

Technical Details

File System Modifications

Tutorials: If you wish to learn how to remove malware components manually, you can read the tutorials on how to find malware, kill unwanted processes, remove malicious DLLs and delete other harmful files. Always be sure to back up your PC before making any changes.

The following files were created in the system:

%Temp%\YontooIEClient.dll

File name: %Temp%\YontooIEClient.dll
File type: Dynamic link library
Mime Type: unknown/dll
Group: Malware file

%Temp%\YontooFFClient.xpi

File name: %Temp%\YontooFFClient.xpi
Mime Type: unknown/xpi
Group: Malware file

%Temp%\YontooLayers.pem

File name: %Temp%\YontooLayers.pem
Mime Type: unknown/pem
Group: Malware file

%Temp%\YontooLayers.crx

File name: %Temp%\YontooLayers.crx
Mime Type: unknown/crx
Group: Malware file

%ProgramFiles%\Yontoo Layers Runtime\YontooIEClient.dll

File name: %ProgramFiles%\Yontoo Layers Runtime\YontooIEClient.dll
File type: Dynamic link library
Mime Type: unknown/dll
Group: Malware file

%Temp%\YontooSetup-Silent.exe

File name: %Temp%\YontooSetup-Silent.exe
File type: Executable File
Mime Type: unknown/exe
Group: Malware file

Registry Modifications

The following newly produced Registry Values are:

HKEY..\..\{CLSID Path}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{DF7770F7-832F-4BDF-B144-100EDDD0C3AE}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{10DE7085-6A1E-4D41-A7BF-9AF93E351401}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{FE9271F2-6EFD-44b0-A826-84C829536E93}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{FD72061E-9FDE-484D-A58A-0BAB4151CAD8}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1AD27395-1659-4DFF-A319-2CFA243861A5}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{10DE7085-6A1E-4D41-A7BF-9AF93E351401}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{D372567D-67C1-4B29-B3F0-159B52B3E967}\1.0HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{FD72061E-9FDE-484D-A58A-0BAB4151CAD8}HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Products\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Products\{DE3B7BF9-0770-4104-BC0B-B1CCCCE2F053}HKEY..\..\{Value}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID\{CFDAFE39-20CE-451D-BD45-A37452F39CF0}\"Default" = "YontooIEClient"HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID\YontooIEClient.DLL\"AppID" = "{CFDAFE39-20CE-451D-BD45-A37452F39CF0}"HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Components\{FC1DD4E4-688F-4E9B-BAE5-BFB6A956AE51}\{DE3B7BF9-0770-4104-BC0B-B1CCCCE2F053}"Default" = "1"HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Components\{A8F0AD53-1AEE-447E-89CD-71C325796F84}\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}"Default" = "1"HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Components\{B6783DFA-B8C8-4CB6-AB9F-EF1A1F7F7AE8}\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}"Default" = "1"HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Components\{9307081B-7444-494C-8CF6-2FA7C0E92BFB}\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}"Default" = "1"HKEY_LOCAL_MACHINE\SOFTWARE\Tarma Installer\Components\{9D9785E5-3424-40B6-A287-BA143AD53109}\{889DF117-14D1-44EE-9F31-C5FB5D47F68B}"Default" = "1"HKEY..\..\..\..{Subkeys}HKEY_LOCAL_MACHINE\SOFTWARE\Classes\YontooIEClient.Api.1HKEY_LOCAL_MACHINE\SOFTWARE\Classes\YontooIEClient.ApiHKEY_LOCAL_MACHINE\SOFTWARE\Classes\YontooIEClient.Layers.1HKEY_LOCAL_MACHINE\SOFTWARE\Classes\YontooIEClient.LayersHKEY_LOCAL_MACHINE\SOFTWARE\Google\Chrome\Extensions\niapdbllcanepiiimjjndipklodoedlc