Threat Descriptions

P2P-Worm:W32/Nugg

Classification

Category :

Malware

Type :

P2P-Worm

Platform :

W32

Aliases :

P2P-Worm:W32/Nugg

Summary

P2P-Worm:W32/Nugg uses the file-sharing application LimeWire to download malware onto the system. It may also use other file-sharing applications to perform the downloads.

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

Installation

During installation, the program drops a file with a name created using the following formula:

  • systemdir\[random dll filename]+ "32.dll"

The program then opens the following services and disables them:

  • wscsvc - the Security Center
  • SharedAccess - Windows Firewall/Internet Connection Sharing(ICS)

It will also load the DLLs into the following processes, provided the processes are running:

  • explorer.exe
  • winlogon.exe
  • iexplorer.exe
  • firefox.exe
  • opera.exe
  • chrome.exe

Activity

While active, the worm attempts to connect to the following domains:

  • 85.17.93.190/conn/[...]
  • nolagtime.com/conn/[...]
  • chewinggym.com/conn/[...]

If successfully connected, it will download an XML file. This file contains URLs leading to files that the worm downloads whenever the system matches certain criteria. The downloaded files are encrypted, though the encryption keys are included in the XML file. The files are malicious and include:

  • https://94.75.234.35/data/[...] - Detected as Trojan.Win32.Agent2.crv
  • https://94.75.234.35/thn/[...] - Detected as Trojan-Downloader.WMA.GetCodec.s

If LimeWire is installed on the infected system, it will be used to download the Trojan.Win32.Agent2.crv file. Other file-sharing applications may also perform this function.

Registry

During installation, the program creates the following registry key:

  • SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\["C:\ drive volume info" + "random number"] value = Dllname data = the dropped file
  • value = Startup data = EventStartup

It also modifies the following registry key as the launchpoint

  • SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows value = AppInit_Dlls data = the dropped file