The NULL file extension is often used for corrupted files, when applications encounter some kind of error NULL files are created automatically.
The NULL file extension can also be used by log files, error or empty files, etc. NULL files occur on various desktop and mobile operating systems.
There is no standard, format or specification which covers .NULL file, therefore, they can be used on multiple platforms, with different encodings and standards, which makes trying to edit these files tricky.
How Windows opens NULL file
When you double-click a file to open it, the first action Windows does is examine the file extension. If Windows recognizes the file extension, it will open it using the program associated with that extension. Otherwise, if Windows does not recognize the file name extension, then you will receive the following message:
Windows cannot open this file
To open NULL file, Windows needs to know which program you want to use to open it.
Normally .null files are not designed to be opened by the user, since they are the result of an error in the execution of a subset of lines of code in a specific program.
Null files and malicious programs, viruses and others
Frequently files with a NULL extension as a side effect of infection by a virus called 'Null', considered a ransomware, which uses the AES-256 algorithm to encrypt user file, thus making it impossible to open the file, and also changes the file extension to .NULL.
The file is literally 'hijacked' and if it is of vital importance to the user, then the user will be forced to pay the cybercriminal an amount to decrypt it. Usually the target files are .docx, .jpg, .mp4, .db, .xlsx, etc.
The ransomware launches a pop-up window with information on the infected files and the amount to pay for decryption. Currently, there are several options for removing the Null virus, but there is no program available to effectively restore infected files. The common thing is that the file is recovered from a backup prior to the disinfection made by the user, however, all the changes made to the file before the infection, would be lost.
Open NULL File on Windows
- Find a NULL file in question in Windows OS File Explorer and double click on it to launch the corresponding application.
- If a NULL file is not opened in an application and you instead get a "Windows can't open a file" error message you should try looking for an application which can open the file in question.
- If you know the application which can open NULL file then run it and see if there is a File, Open main menu option in the application.
- If you do not know the application which function as NULL file opener then try to search for "NULL wiki", "application to open NULL file" or "open NULL file" queries in the search engine you like.
- Install the application you found and check if it can open NULL file
Open NULL File on Android
If you downloaded a NULL file on Android device, you can open it by following the steps below:
- In the Android apps list on your Android device find ‘My Files’ or ‘File manager’ app and tap to start it.
- Tap on ‘Downloads’ folder inside the app.
- You should see your downloaded NULL file in that folder.
- Tap on the file. If Android device supports opening the file you downloaded it will open in the corresponding app.
- If file does not open you can look for the corresponding app that can open the file by searching Android App Store for the ‘NULL’.
- If you cannot open the file with the apps from Android App Store it is possible that the file could only be opened on desktop platforms such as Windows or Mac OS. Try searching the internet for ‘NULL file’ and see if any desktop applications can open it.
- It is also possible that the file you downloaded is outdated and is no longer supported.
Open NULL File on iPhone or iPad
To open NULL File on iOS device follow steps below:
- Open Files app on your iPhone or iPad device. You can find it by swiping down on the home screen and typing ‘Files’ in the search bar.
- Tap on the Downloads folder on the Files app home screen.
- You will see all files that you recently downloaded. Tap on the NULL file to view it.
- If you have the right app that can open it, it will automatically launch and open your file.
- If you do not have the app which can open it you need to search Apple app store for ‘NULL’. This way you can find apps which can open NULL files.
- If this does not help it is possible that your file could be opened only by the desktop application. To find an app which can open it on desktop look for ‘NULL file’ in your favorite search engine.
What does Null File Path mean?
Null file path during an LTO process means:
- The file(s) has/have been changed or altered or sent offline while the backup is running so the backup job will not be able to find the file(s).
- The file(s) or folder(s) contain illegal characters that the Windows OS are not accepting and must be altered for the OS to process the backup
- The file(s) and folders(s) are too long in length or are too deep in file path that it considers the character count too long
Windows Server 2012: 255 for both files and folders combined for the entire path.
Windows Server 2016: 255 for individual files/folders. Total for path has an extremely high limit.