Trojan-Dropper:W32/Agent.REK

Classification

Category :

Malware

Type :

Trojan-Dropper

Aliases :

Trojan-Dropper:W32/Agent.REK, Trojan-Dropper.Win32.Agent.rek

Summary

Agent.REK drops and executes other malware applications on the infected system, thus compromising system security.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

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 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.

Technical Details

Upon execution, Agent.REK drops and executes the following files:

  • %System%\WinNt32.dll
  • %System%\drivers\[Random Filename].sys

Note: %System% represents a path that is typically C:\Windows\System32. Note: [Random Filename] represents a randomly generated filename used by the trojan at the time of infection, such as Oiv23.sys and Tqy10.sys. The dropped files are detected as Trojan-Downloader.Win32.Agent.GLH and Trojan-Dropper.Win32.Agent.REK respectively. This Trojan creates the following registry entries as part of its installation:

  • HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\WinNt32 DLLName = "WinNt32.dll" StartShell = WLEventStartShell
  • HKLM\SYSTEM\CurrentControlSet\Services\[random filename] ImagePath = "%System%\drivers\[random filename]
  • HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\[random filename].sys (default) = Driver
  • HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\[random filename].sys (default) = Driver

Trojan-Downloader.Win32.Agent.GLH then attempts to connect to the following IP addresses:

  • 208.66.195.15
  • 217.170.77.146
  • 66.232.113.80

Additional Note

Files detected as Trojan-Dropper.Win32.Agent.slh have the same characteristics as Agent.REK.