fman 1.4.4 and Windows Defender


Microsoft have fixed the erroneous detection. If you still encounter problems, please follow these steps to clear the cache and obtain the latest malware definitions:

  1. Open a command prompt as Administrator and navigate to c:\Program Files\Windows Defender.
  2. Run MpCmdRun.exe -removedefinitions -dynamicsignatures.

Alternatively, the latest definitions are available for download here.

Unfortunately, Windows Defender thinks fman 1.4.4, which came out two days ago, is malware. Specifically, it claims fman is infected by Trojan:Win32/Tiggre!plock. The same happens for Microsoft Security Essentials on earlier versions of Windows.

Of course, fman is not a virus. I have given ample justification for this in an earlier blog post. The short summary is that fman is not an elaborate scheme to get malware onto your computer. It's a mission to create the world's best file manager.

Just to be safe I'm not inadvertently spreading viruses, I updated Microsoft Security Essentials to the latest version and ran a full check of my system. The only thing it "found" was fman itself:

I've submitted fman as a false positive to Microsoft. Hopefully, they will be able to simply update their virus definitions. In the meantime, to get fman working again, you will have to tell Windows Defender (/MS Security Essentials) that it's not a threat.

As for the "cause" of the problem, it seems to be that fman now uses a newer version of PyInstaller, the library that turns fman's source code into a standalone executable. Other developers are having the same problem. (For future reference: fman's PyInstaller version was updated from 3.3 to 3.4.)

I'm sorry if this affects you. It's very frustrating for me as well.

Michael started fman in 2016, convinced that we deserve a better file manager. fman's launch in 2017 was a huge success. But despite full-time work, it only makes $500 per month. The goal is to fix this.