internemt temp

So is there a way i could make a malicious file that will initiate when a program is downloaded. While it downloads it will go into the temp files and then it will copy itself into another location from there. C:/Windows.

As in it watches the downloads waiting for a certain file to be downloaded? you can set up watches on the file system, vb.net makes it really easy you can apply handlers that trigger when a file is added to a folder or whatnot.

or do you mean it runs itself when downloaded? if that was easy, then none of us would be secure at all right now would we? so no. i mean it all depend on the browser, but unless you find a weakness yourself, like a 0day then no you cant.

because they would patch that shit up in 2 seconds if that existed.