System information

Threats to computer security 23
TYPE
NAME
DESCRIPTION
Trojan-
Droppers
Trojan program-
droppers
These programs save programs
containing other Trojan programs on the
computer's disk and then install them.
Intruders can use Trojans-Droppers in
different ways:
 to install malware programs without
the user's knowledge: Trojans-
droppers either do not display any
messages, or display false messages,
for example, notifying about an error
in an archive or about using the wrong
version of the operating system;
 to protect another known malware
program from being detected: not
every anti-virus program can detect a
malware program located inside a
trojan-dropper.
Trojan-
Notifiers
Trojan-notifiers
They notify the intruder that the infected
computer is connected; and then transfer
information about the computer to the
intruder, including: IP address, number of
an open port or the e-mail address. They
communicate to the intruder using a
number of methods including e-mail,
FTP, and by accessing the intruder's web
page.
Trojan-notifiers are often used in sets of
complementary Trojan programs. They
notify the intruder that other Trojan
programs are successfully installed on
the user's computer.