sent strange file

I sent a suspicious file that i thought might be a virus to avast but i did not know how to password protect this file how can i password protect them so next time i will know how.

That totally depends on the program you are using to zip the file up?

A search of the zip programs help file for Password should give some information.

Now this is an example why we need online based upload form for suspicios files.
I’m tired of explaining how to protect each and every file. And i belive others share the same opinion with me.