A trojan was recently discovered on a server. There are now concerns that there has been a security breach
that allows unauthorized people to access data. The administrator should be looking for the presence of a/an:
There has been a security breach on a computer system. The security administrator should now check for the
existence of a backdoor.
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