FileUnsigner – Remove digital certificates from files
This small tool was created to simplify the process that was discussed at Remove digital signature from a file using C# and simply aid the people that didn’t have the knowledge on how to compile the code posted there.
This is a small standalone tool that will simply remove the digital signature of any file.
The usage is fairly simple. Either drag and drop the files you want to unsign on the application or use command prompt with the following parameters:
FileUnsigner.exe <options> <file1> <file2> …
/f Forces the program to remove a digital signiture even if one is not detected.
You will find a download link for FileUnsigner below.
Thank you so much.
More than great
thank you for this app.
Is the latest version from 2013 220.127.116.11>? Win10 doesn’t seem to recognize it and I get a cmd prompt message saying to d’load the latest version which this seems to be. Thanks!
The latest version is 18.104.22.168 from 2013 as you mentioned. You shouldn’t be getting a prompt to download anything as there is no update checking in the software.
Using it on Windows 10 to install Malwarebytes. The drag and drop seemed to work, I got the cmd line response that said the unsigning was successful. When I clicked on the file to install the program, I get an error code:
Unable to execute in the temporary directory. Error 170: The requested resource is in use.
Seems like other people have the same problem, see https://www.reddit.com/r/techsupport/comments/670cre/cant_install_malwarebytes/ and https://forums.malwarebytes.com/topic/197305-requested-resource-is-in-use/ for example.
By the looks of it, this seems like a situation where either a program is blocking you from accessing the temporary folder (which Malwarebytes requires access in order to extract the files) or your file/folder permissions have been modified.
Hello. This works great on exe files, but doesn’t seem to work on .msi files. Is there any way to remove a digital cert from the .msi file? Thanks.
Anyone having trouble unzipping the file? It does not give me an option to unzip on both my laptop and desktop that both run windows 10.
it’s a .rar file. install 7zip and use that for all compression/decompression types. if the file isn’t associated by default, right-click on the file and choose “extract to…”
Is there a way to remove specific digital signatures from a file that contains more than 1 digital signature? For example, if a file had 2 digital signatures, is it possible to remove only 1 of the 2, leaving the remaining digital signature present?
Currently no. FileUnsigner will always remove the the signature at index 0.
Thank you for the feedback though. I might implement the “list signatures” / “remove specific signatures” functionality as it sounds like a nice feature to have.
As for now, if you know the index of the signature, you can hardcode the index in line 74, compile the software and then run it.
Pull requests are always welcome.
Thank you for your reply with the additional information. I think “list signatures” / “remove specific signatures” options would add significant value. In the meantime, I will try your suggestion to edit line 74 and specify the index #; is there a way to determine the index number by looking at the signature properties? Or, do the signatures simply go in numerical order, e.g. index 0, index 1, index 2, etc.?
I don’t think the Windows UI exposes the index sadly.
You will need to use the ImageEnumerateCertificates function to get the index of the signatures.
Hello, I’m using this command as a Windows administrator “FileUnsigner.exe file.cat” to remove the digital signature from a .cat (driver catalog) file.
If I ran the command multiple time, the command output is always the same, and seems that the signature is not removed from the file: “RESULTS: 0: Successfully unsigned file.cat” while the digital signature tab is still present on file properties.
Same result with /f option.
Any suggestion is welcomed.
One possibility might be that the actual index of the certificate is not 0.
A change was suggested by ahmd at http://www.fluxbytes.com/csharp/remove-digital-signature-from-a-file-using-c/#comment-2021 but it has not been implemented as of yet.
Thank you for your answer.
I hope this change may be implemented soon.
It keeps exiting out of the FileUnsigner when I drag the file onto it.
Can someone please help me with this?
FileUnsigner shouldn’t just exist without any message. Something else is going on here.
What happens if you run FileUnsigner from command prompt (cmd.exe) with the relevant arguments? Does it display more information?
Example: C:\FileUnsigner.exe “C:\SignedFile.exe”
Do you mind providing me more information/details on how to run FileUnsigner from command prompt?
Worked perfectly! Had been trying to install new driver file for wifi card for 2 weeks until I found this. Awesomely simple. :)
Doesn’t seem to work any more. Tried using it on HP Recovery Manager and it reports that it doesn’t appear to be digitally signed.
Neeeevermind, user error. Please disregard or delete both comments. Thanks for the handy tool.
Thanks! It worked fine.
Brilliantly simple. It just works. Download Now!
Thanks, CoolMinE, worked – enabled me to re-install SQLBakUPftp . . .
now wretched Windows 10 has blocked it again “for my security” :(
Any ideas what I could try next?
Hard to say without being able to replicate the problem sadly. I have the SmartScreen featured disabled so I never get these “warnings”.
My guess would be that, even if you unsigned the installer, therefore allowing you to install SQLBakUPftp, the files that were installed are probably signed as well. You can start by verifying if this is the case and trying to remove the certificates for those files as well.
Fantastic Util. Saved my bacon
Always happy to save a bacon in distress !
I want to remove digital signature from .pdf file. Will fluxbyte be useful?
Trojan Virus high level
Assuming you have downloaded the software from our page and not from somewhere else, this is a false positive from your Antivirus.
Since this software is open source you can always build the source yourself if you don’t trust it. See https://github.com/CooLMinE/FileUnsigner
Thank you for the tool. It enabled old drivers to be installed on Win 10
Great! it works
I was wondering, how am I able to use this on a windows system file, without getting an access denied message?
Access denied probably means that you are not running the program as administrator. Lunch command prompt as an admin then call the program with the needed parameters as usual.
Works flawlessly, thank you for the tool
love the drag and drop functionality extremely easy to use