It's a malware, and it basically let's the person/hacker/culprit get information off your computer without the owner of the computer knowing that the person is doing it. It's often used to find keystrokes, passwords, online interaction, and other personal data.
Availability ,devices and applications, performance, security, scalability.
Answer:
Header is at the top of the page and used for epicas and titles, while footers at the bottom are used for footnotes or page number
Answer:
000000000000000000000000000001111111111111111111
Technically: a forward DNS lookup
They're probably just looking for DNS
