Threat Description



Category: Malware
Type: Worm
Platform: W32


A standalone malicious program which uses computer or network resources to make complete copies of itself.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.


Detailed instructions for F-Secure security products are available in the documentation found in the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for further assistance.

Technical Details


Upon execution, the malware first creates a copy of itself in the program files, then amends the registry to ensure automatic execution.

It also creates the following files in all removable drives found in the system:

  • system.exe
  • autorun.inf

The system.exe file is a copy of itself, while the autorun.inf contains the following strings:

  • [autorun]open=system.exeshellexecute=system.exeshell\Explore\command=system.exeshell\Open\command=system.exeshell=Explore

The malware attempts to download files from:


Note: %VolumeSerialNumber% is volume serial number that the operating system assigns when a hard disk is formatted.


For its stealth routine, it injects malicious code into the one of the following normal process:

  • svchost.exe
  • %program%

Note: %program% is usually "C:\Program Files\Internet Explorer\IEXPLORE.EXE -nohome" which was taken under the registry key "HKEY_CLASSES_ROOT\http\shell\open\command, (Default)".It also removes the hooked addresses corresponding to various NT Functions implemented in Ntoskrnl.exe, then restores them to their original values.

The malware will attempt to make the changes by exploiting the GDI Local Elevation of Privilege Vulnerability (CVE-2006-5758), which in unpatched machines allows a remote attacker to gain direct access to the kernel. If this method fails, it drops and executes a special driver that restores the pointers:

  • NtProtectVirtualMemory
  • NtOpenThread
  • NtTerminateThread
  • NtCreatePort
  • NtConnectPort
  • NtCreateKey
  • NtAdjustPrivilegesToken
  • NtCreateFile
  • NtWriteVirtualMemory
  • NtOpenProcess
  • NtCreateProcess
  • NtCreateProcessEx
  • NtCreateSection
  • NtCreateThread
  • NtDeleteKey
  • NtDeleteValueKey
  • NtDuplicateObject
  • NtEnumerateKey
  • NtEnumerateValueKey
  • NtLoadDriver
  • NtLoadKey
  • NtLoadKey2
  • NtNotifyChangeKey
  • NtOpenFile
  • NtOpenKey
  • NtOpenSection
  • NtQueryKey
  • NtQueryMultipleValueKey
  • NtQueryValueKey
  • NtReplaceKey
  • NtRestoreKey
  • NtResumeThread
  • NtSaveKey
  • NtSetContextThread
  • NtSetInformationFile
  • NtSetInformationKey
  • NtSetSystemInformation
  • NtSetValueKey
  • NtSuspendThread
  • NtSystemDebugControl
  • NtTerminateProcess

The malware creates and executes a kernel service driver as either of the following:

  • %systemdir%\Drivers\%servicename%.sys
  • %service_path_and_filename%

Both these files are detected as Rootkit:W32/Agent.UG.

It will query all services under the following registry entries, to obtain the %service_path_and_filename% and %servicename% of services that have:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\%servicename%

It also creates the following registry entries to bypass the Windows Firewall:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List{malware_executed_path_and_filename} = "{malware_executed_path_and_filename}:*:Enabled:EMOTIONS_EXECUTABLE"

Additionally, it creates a window with Classnames= "WNDCLASSXEMORES".

Description Created: 2008-09-16 04:01:00.0

Description Last Modified: 2010-08-02 08:00:27.0


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