Files with def file extension are related to the IOBit Malware Fighter and used for its definition data.

There are 5 other file types using
the DEF file extension!

empty icon.def - Definition data

empty icon.def - Data Entry/Review Module file

empty icon.def - NovaLogic game weapon profile

empty icon.def - ESwin wizard file

empty icon.def - id Tech 6 video settings

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DEF file extension - IOBit Malware Fighter definitions

What is def file? How to open def files?

File type specification:

Various data file type icon Various data file type

The def file extension is associated with the IOBit Malware Fighter, a software for Microsoft Windows operating system, which is able to detect and remove malware from PC.

The def file contains malware definitions for Malware Fighter.

The default software associated to open def file:

IObit Malware Fighter icon

IObit Malware Fighter  Microsoft Windows software

Company or developer:

IObit Malware Fighter is malware removal and browser secure utility that detects and removes infections and users' most concerned online threats, and protects browser from potential malicious behavior in real time.

Help how to open:

This file type is not meant to be opened directly, there is no software that could open and work with it directly, or there is no information available in public sources about opening this file type. This is usually the case of some internal data files, caches, temporary files etc.

How to convert:

As far as we know, this .def file type can't be converted to any other file format. This is usually the case of system, configuration, temporary, or data files containing data exclusive to only one software and used for its own purposes. Also some proprietary or closed file formats cannot be converted to more common file types in order to protect the intellectual property of the developer, which is for example the case of some DRM-protected multimedia files.

List of recommended software applications associated to the .def file extension

Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open def file, edit def file, convert def file, view def file, play def file etc. (if exist software for corresponding action in's database).

Unspecified and all other actions for computer programs working with def file - IOBit Malware Fighter definitions

Click on the software link for more information about IObit Malware Fighter. IObit Malware Fighter uses def file type for its internal purposes and/or also by different way than common edit or open file actions (eg. to install/execute/support an application itself, to store application or user data, configure program etc.).

Microsoft Windows:

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