JK0-022 Free Dumps Study Materials
Question 20: Two programmers write a new secure application for the human resources department to
store personal identifiable information. The programmers make the application available to
themselves using an uncommon port along with an ID and password only they know. This is an
example of which of the following?
A. Root Kit
B. Spyware
C. Logic Bomb
D. Backdoor
Correct Answer: D
Explanation:
A backdoor in a computer system (or cryptosystem or algorithm) is a method of bypassing normal
authentication, securing unauthorized remote access to a computer, obtaining access to plaintext,
and so on, while attempting to remain undetected. The backdoor may take the form of an installed
program (e.g., Back Orifice) or may subvert the system through a rootkit. A backdoor in a login
system might take the form of a hard coded user and password combination which gives access to
the system. Although the number of backdoors in systems using proprietary software (software
whose source code is not publicly available) is not widely credited, they are nevertheless frequently
exposed. Programmers have even succeeded in secretly installing large amounts of benign code as
Easter eggs in programs, although such cases may involve official forbearance, if not actual
permission. Many computer worms, such as Sobig and Mydoom, install a backdoor on the affected
computer (generally a PC on broadband running Microsoft Windows and Microsoft Outlook). Such
backdoors appear to be installed so that spammers can send junk e-mail from the infected machines.
Others, such as the Sony/BMG rootkit distributed silently on millions of music CDs through late 2005,
are intended as DRM measures-and, in that case, as data gathering agents, since both surreptitious
programs they installed routinely contacted central servers.