Intent filter's pathPattern not working as expected

I'm trying to support .vyb files in my application (from mail) and added this intent filter for that.

<data
     android:mimeType="application/octet-stream"
     android:pathPattern=".*\\.vyb"
     android:scheme="content" />

But its also oppening the .mobi files. File's full name is something like mybook.lc.mobi.

I'm not sure what's the problem here, can someone help me understand the problem here?