No. Whenever you create a new file the
umask is applied. This
umask is a number that dictates what permissions will the file have.
For having execution permission masks should be either
3. No file is created with those masks. But, beware of compressed files, since those keeps their file permission when you extract them. If you keep downloading things from trusted sources and verify the content before doing anything, you should be alright.
Let's see how umask works:
For files the default mask is
0666 and the umask is
0022. The system each time you create a file do this operation:
mask - umask = file permissions
0666 - 0022 = 0644
The permissions numbers broken down is like follows:
|||\_ others permissions, in this case only read
|| \__ groups permissions, in this case only read
| \___ user permissions, in this case read and write
\__ special byte
Hence, each file created by your user is created so you can read and write the file, your group can read them, and others can read them too. Nothing to do with the executables.