Email-Worm:W32/Agent.EV

Classification

Category:

Malware

Type:

Email-Worm

Platform:

W32

Aliases:

Email-Worm:W32/Agent.EV

Summary

Email-Worm.Win32.Agent.ev arrives on systems as an email attachment and attempts to download additional components onto the system if executed.

Removal

Automatic action

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.

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.

For more Support

Community

Find the latest advice in our Community.

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

Email-Worm:W32/Agent.EV spreads as an attachment in spam email with attention grabbing lines in the subject field.

The following email subjects have been observed:

  • Hot News
  • Hot Pictures
  • Paris Hilton
  • Something Hot

The attachment is named Saver.zip.

When the malware is extracted and executed, it will drop the following components:

  • %Windir%\System32\WinNt32.dll
  • %Windir%\System32\WinData.cab\
  • %Windir%\System32\drivers\[name].sys

%Windir% is the Windows directory. This is usually C:\Windows.[name] is a random filename. Observed examples are Mvd37.sys and Irv31.sys. The contents of the files are the same.WinData.cab is a copy of WinNt32.dll.

All of the dropped components are detected asTrojan-Downloader:W32/Agent.NSL.

The following registry entries are created to load WinNt32.dll on every system startup:

  • HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\WinNt32DLLName = WinNt32.dllStartShell = WLEventStartShellImpersonate = 00000000Asynchronous = 00000000ID = 0000003C

The following registry entries are created to start the [name].sys file as a service:

  • HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\[name].sys (default) = Driver
  • HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\[name].sys (default) = Driver
  • HKLM\SYSTEM\CurrentControlSet\Services\[name]Type = 00000001Start = 00000003ErrorControl = 00000000ImagePath = System32\drivers\[name].sys

Similar changes are made in HKLM\SYSTEM\ControlSet001\Services\[name] and HKLM\SYSTEM\ControlSet002\Services\[name].

The Trojan-Downloader:W32/Agent.NSL DLL component will then attempt to connect to one of the following addresses:

  • 66.232.113.80
  • 208.66.195.15

Other slightly modified variants may attempt to connect to different addresses.