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What is npf?

Npf.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the OS, hardware etc.
The free file information forum can help you determine if npf.sys belonging to the Windows system or an application you can trust.

Run a free scan to check for npf drivers in need of updating

Npf.sys file information

The process known as npf.sys (NT5/6 (version x86) Kernel Driver) or npf.sys (NT5/6 AMD64) Kernel Driver or NPF Driver - TME extensions

belongs to software NetGroup Packet Filter Driver or WinPcap Netgroup Packet Filter Driver or NPF Driver

by CACE Technologies (www.cacetech.com) or Politecnico di Torino or NetGroup - Politecnico di Torino or Riverbed Technology.

Description: Npf.sys is not essential for the Windows OS and causes relatively few problems. The file npf.sys is located in the folder C:\Windows\System32\drivers. Known file sizes on Windows 7/XP are 32,512 bytes (43% of all occurrences), 35,088 bytes and 13 more variants. http://www.file.net/process/npf.sys.html 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program has no visible window. The service has no detailed description. The file is not a Windows core file. There is no file information. npf.sys seems to be a compressed file. Therefore the technical security rating is 24% dangerous, however also read the users reviews.
You have the option to uninstall the program using the Control Panel ⇒ Add/Remove programs ⇒ WinPcap.

Recommended: Identify npf.sys related errors

Important: Some malware disguises itself as npf.sys, particularly when not located in the C:\Windows\System32\drivers folder. Therefore, you should check the npf.sys process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

Part of a packet sniffer librarie WinPCap (here installed by a WM media capturing program WM Recorder 10)
Used by WinPcap, an open-source windows packet capturer
  David   (further information)
part of WinPcap
as said before - this is part of the winPCap library - if you use a Ethereal, this file is vital
  frederic   (further information)
Confirm David -- installed by WinPcap
used by winPcap Pretty safe.
  Brendan   (further information)
it belongs to WinPcap, an Network-Packet Sniffer (OpenSource)
  RanuKanu   (further information)
If you know why WinPcap is installed, this isn't a problem. Otherwise...
  Dave   (further information)
Part of the WinPcap package, is also installed by software that needs a virtual LAN
used by Ethereal via Wi Fi Defense application
Part of installed Winpcap
npf.sys on windows xp is a hijacking malware item. I removed the file from c:\windows\system32 and no longer get hijacked to an unwanted website.
Someone hacked into my server and noticed in the event viewer this: The NetGroup Packet Filter Driver service was successfully sent a start control.
npf.sys is a file of Winpcap
  Mohd Akram  
I think it's ok. I have Wireshark and I wanted to use it lately but it didn't start and now I can see that ComboFix qurantained this file.
Because of npf.sys my System (Vista) did not want to start anymore... could not repair it, so I need to install Windows completly new. (The Problem startet after Windows Update on 10.03.10)
Possibly harmful - ComboFix detects it as Malware and removes it
Used by Devolo dLAN - networking via power sockets
  Dave Horton  

Rating chart

Summary: Average user rating of npf.sys: based on 22 votes with 18 user comments.
13 users think npf.sys is essential for Windows or an installed application. 2 users think it's probably harmless. 3 users think it's neither essential nor dangerous. 2 users suspect danger. 2 users think npf.sys is dangerous and recommend removing it. One user is not sure about it.

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Npf scanner

Security Task Manager shows all running Windows tasks including embedded hidden functions (e.g. keyboard or browser monitoring, autostart entry). A unique security risk rating indicates the likelihood of the process being potential spyware, malware, keylogger or a Trojan.

Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, trojans, keyloggers, malware and tracking threats from your hard disk. Ideal supplement to Security Task Manager.

SpeedUpMyPC scans, cleans, repairs and optimizes your computer.

Other processes

npf.sys [all]