Melissa and LoveLetter made use of the trust that exists between friends or colleagues. Imagine receiving an (6) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (7) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’address book, previous emails, web pages (8) .
As administrators seek to block dangerous email attachments through the recognition of well-known (9) , virus writers use other extensions to circumvent such protection. Executable(.exe)files are renamed to .bat and .cmd plus a whole list of other extensions and will still run and successfully infect target users.
Frequently, hackers try to penetrate networks by sending an attachment that looks like a flash movie, which, while displaying some cute animation, simultaneously runs commands in the background to steal your passwouds and give the (10) access to your network.

A．names

B．cookies

C．software

D．extensions