Home windows File Explorer offers a ton of choices to alter the way you view your information. What you won’t know is {that a} vital possibility is disabled by default, regardless of being important to your system’s security.
File Extensions Are Essential
File extensions are three or four-letter suffixes that seem after the ultimate interval of a file title, reminiscent of .txt, .exe, or .pdf. These extensions act as identifiers so the OS (and also you) can inform at a look what sort of file they’re.
Home windows makes use of file extensions to find out which app ought to launch while you double-click a file. For instance, an .exe file will launch an utility, whereas a .docx file will open a Phrase file in Microsoft Phrase. Numerous applications save information in their very own distinctive file extensions, which may then solely be opened in that program (or a appropriate third-party software).
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A key benefit of with the ability to see file extensions is the power to identify doubtlessly harmful information. Sure extensions like .exe, .bat, .cmd, .vbs, and .scr (amongst others) will be harmful information designed to run malicious code in your system. Such information usually make use of file extensions utilized by official Home windows instruments and applications, so recognizing them will be difficult.
Regardless of their significance, file extensions are hidden by default in all fashionable variations of Home windows. That is completed to create a cleaner consumer interface inside File Explorer. Nonetheless, malware creators usually use hidden extensions to disguise malicious executable information as seemingly innocent paperwork to trick you into working malware in your PC, so it is significantly better to have them seen.
Displaying File Extensions on Home windows
Fortunately, enabling file extensions on Home windows takes just a few clicks. On Home windows 11, merely open File Explorer by utilizing the Home windows key + E keyboard shortcut, click on View within the prime bar, hover over Present, and choose File title extensions. It is best to begin seeing file extensions for all information saved in your PC.
In case you do not see the highest bar in File Explorer, you may as well allow file extensions from Home windows settings. Observe these steps:
- Press Home windows key + I to open Home windows Settings. Head to the System tab and choose For builders.
- Increase the File Explorer part by clicking it, then ensure the Present file extensions slider is turned on.
Particualrly in case you’re utilizing an older model of Home windows, the Management Panel additionally turns out to be useful for enabling file extensions:
- Open the Begin menu and seek for Management Panel. Click on the corresponding possibility.
- Change Class to Small icons if wanted, then select File Explorer choices.
- Underneath the View tab, make it possible for the Disguise extensions for identified file sorts possibility is unchecked.
It’s also possible to allow file extensions by making a small change to the Home windows registry, however I like to recommend avoiding this. The three strategies above ought to work on any model of Home windows you are utilizing in 2025, and are a lot much less susceptible to error. Nonetheless, if you need a fast approach of enabling file extensions, merely run this command in both the Home windows Terminal or PowerShell:
reg add HKCUSoftwareMicrosoftWindowsCurrentVersionExplorerAdvanced /v HideFileExt /t REG_DWORD /d 0 /fThis command will add the required entries to the Home windows registry that inform File Explorer to start out displaying file extensions. Ensure that to refresh File Explorer utilizing the F5 key to see the modifications.
How Attackers Exploit Hidden File Extensions
As talked about, hackers usually exploit hidden file extensions on Home windows to disguise malicious information as harmless ones. For instance, a file named picture.png.exe will seem as a PNG picture file in File Explorer with file extensions hidden, when in actuality it is an executable file that may run malicious code or malware when launched.
This system is named a “double extension assault” and is the most typical kind of extension assault you will see. Fortunately, so long as file extensions are enabled, these malicious EXE information are fairly straightforward to identify and keep away from. Nonetheless, that is removed from the one approach that tries to make use of hidden extensions to confuse you. Another fashionable strategies embrace:
Method
Instance
Description
Proper-to-Left Override (RTLO)
picture[RTLO]gpj.exe seems as picture.exe.jpg
Attackers use the Unicode character U+202E to reverse the file title.
Whitespace Padding
doc.pdf[insert 100 spaces].exe
You’ll be able to place a number of areas between the faux and actual file extension, so the actual extension will get pushed off-screen even when file extensions are enabled.
Icon Manipulation
doc.exe file with a PDF icon
This can be a easy approach the place a prison swaps out the icon of a malicious file for one thing extra acquainted, reminiscent of a PDF or JPG icon.
PIF Information
doc.pif
PIF file extensions are robotically hidden by Home windows, even when file extensions are enabled. That mentioned, PIF information are hardly ever utilized in fashionable Home windows variations.
As you may see, there are many tips attackers can use to trick you into working a malicious executable you may suppose is a picture. Nonetheless, by spending just some seconds enabling file extensions on Home windows, you may catch these traps earlier than unintentionally launching any malware in your PC.
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Cease settling for a subpar Home windows expertise.
File extensions assist determine what kind of file you are coping with, however Microsoft’s selection to cover them by default in File Explorer opens the door for fraudsters to disguise malicious information. Don’t fall for these tips. Allow file extensions and at all times double-check a file earlier than opening it, particularly if it got here from the web otherwise you did not ask for it.
