if you think you might be infected with something, it could include a keylogger. If you type in the password field, it will pick it up. But if you type up a document, it will think its just a document. So... type a couple of sentences and include your desired password, then copy it from the sentence and paste in the password field. (Key loggers can't see what you pasted.) If you use formats like rGj3Rt that will look like a password, type several sets of 'garbage words' and include your password in the middle of one of the words - Hg67Jyt*iloJL9I7Y% Fg54&j*oNgY64R#$jK8 Lji8KyrGj3RtVbnJ5U79 - and copy the section that is going to be the password and paste in the dialog. (i have the password in bold only so you can see where it is here). You could type up normal sentences and copy letters from the document and paste elsewhere in the doc or in notepad to create the password, which you copy and paste in the password field.