Files with def file extension are related to the IOBit Malware Fighter and used for its definition data.
DEF file extension - IOBit Malware Fighter definitions
What is def file? How to open def files?
File type specification:
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:
Company or developer:
IObit
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.
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 File-Extensions.org'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.).