Trojan:W32/Agent.ARKD

Classification

Malware

Trojan

W32

Trojan:​W32/Agent.ARKD, Trojan.Agent.ARKD, Trojan.Generic.5594507

Summary

Trojan:W32/Agent.ARKD attempts to connect to a remote host and download an additional malicious file onto the infected system.

Removal

Manual removal

  1. Open the Registry Editor. To do so, select Run from the Start Menu; type "regedit" into the Open: field and click OK.
  2. Once the Registry Editor has launched, navigate to the following registry key:
    • HKLM\System\CurrentControlSet\Services\srv[numbers]
  3. Check if the servicedll value in the registry key's parameters is:
    • %temp%srv[numbers].tmp
  4. If the servicedll value is as above, right-click on the icon for the srv[numbers] folder in the Registry Editor's navigation pane, and then select "Permission...".
  5. In the Permissions menu, click on SYSTEM under "Group or user names:"
  6. In the Permissions for SYSTEM menu, check the Deny box for Full Control, and then click Apply.
  7. Go back to the servicedll value in the registry key's parameters, right-click on it and select Delete.
  8. Refresh the page by pressing the F5 key to make sure the servicedll value is not recreated.
  9. Reboot the system.
  10. On Windows startup, perform a full computer system scan with F-Secure Anti-Virus.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

The associated detections Trojan.Agent.ARKD and Trojan.Generic.5594507 both triggered on a DLL file named setup50045.fon, which was associated with a malware attack.

Execution

Upon execution, setup50045.fon drops a copy of itself in the following directory:

  • %temp%\srv[numbers].ini
  • %temp%\srv[numbers].tmp (hidden)

It will then set itself as a launch point service by setting the following values in the registry:

  • HKLM\System\CurrentControlSet\Services\srv[numbers] ImagePath = %systemroot%\system32\svchost.exe -k netsvcs
  • HKLM\System\CurrentControlSet\Services\srv[numbers] servicedll= %temp%\srv[numbers].tmp

Network Connection

Once installed, the malware attempts to establish connection with the following remote hosts:

  • 77.79.9.91
  • 109.235.49.103
  • 178.32.189.105

It downloads a malicious executable file from the link below:

  • https://178.32.189.105/service/[...]/[...]/aff_50045.dll

The downloaded executable is detected as Trojan.Agent.ARKE.