<s>
Trojan.Win32.DNSChanger	B-Protocol
is	O
a	O
backdoor	O
trojan	O
that	O
redirects	O
users	O
to	O
various	O
malicious	O
websites	O
through	O
the	O
means	O
of	O
altering	O
the	O
DNS	B-Protocol
settings	O
of	O
a	O
victim	O
's	O
computer	O
.	O
</s>
<s>
DNS	B-Protocol
changer	O
trojans	O
are	O
dropped	O
onto	O
infected	O
systems	O
by	O
other	O
means	O
of	O
malicious	O
software	O
,	O
such	O
as	O
TDSS	O
or	O
Koobface	O
.	O
</s>
<s>
Therefore	O
,	O
it	O
performs	O
several	O
actions	O
on	O
behalf	O
of	O
the	O
attacker	B-General_Concept
within	O
a	O
compromised	O
computer	O
,	O
such	O
as	O
changing	O
the	O
DNS	B-Protocol
settings	O
in	O
order	O
to	O
divert	O
traffic	O
to	O
unsolicited	O
,	O
and	O
potentially	O
illegal	O
and/or	O
malicious	O
domains	O
.	O
</s>
<s>
The	O
Win32.DNSChanger	B-Protocol
trojan	O
is	O
used	O
by	O
organized	O
crime	O
syndicates	O
to	O
maintain	O
click	O
fraud	O
.	O
</s>
<s>
The	O
trojan	O
is	O
commonly	O
found	O
as	O
a	O
small	O
file	O
(+/	O
-	O
1.5	O
kilobytes	O
)	O
that	O
is	O
designed	O
to	O
change	O
the	O
NameServer	B-Protocol
registry	B-Protocol
key	I-Protocol
value	O
to	O
a	O
custom	O
IP	B-Protocol
address	I-Protocol
or	O
domain	O
that	O
is	O
encrypted	O
in	O
the	O
body	O
of	O
the	O
trojan	O
itself	O
.	O
</s>
<s>
As	O
a	O
result	O
of	O
this	O
change	O
,	O
the	O
victim	O
's	O
device	O
would	O
contact	O
the	O
newly	O
assigned	O
DNS	B-Protocol
server	I-Protocol
to	O
resolve	O
names	O
of	O
malicious	O
webservers	B-Application
.	O
</s>
<s>
Trend	O
Micro	O
described	O
the	O
following	O
behaviors	O
of	O
Win32.DNSChanger	B-Protocol
:	O
</s>
<s>
A	O
user	O
who	O
wants	O
to	O
visit	O
the	O
iTunes	B-Operating_System
site	O
,	O
for	O
instance	O
,	O
is	O
instead	O
unknowingly	O
redirected	O
to	O
a	O
rogue	O
site	O
.	O
</s>
<s>
F-Secure	O
,	O
a	O
cybersecurity	O
company	O
,	O
received	O
samples	O
of	O
a	O
variant	O
that	O
were	O
named	O
PayPal-2.5.200-MSWin32-x86-2005.exe	B-Protocol
.	O
</s>
<s>
The	O
trojan	O
was	O
programmed	O
to	O
change	O
the	O
DNS	B-Protocol
server	I-Protocol
name	O
of	O
a	O
victim	O
's	O
computer	O
to	O
an	O
IP	B-Protocol
address	I-Protocol
in	O
the	O
193.227.xxx.xxx	O
range	O
.	O
</s>
<s>
The	O
registry	B-Protocol
key	I-Protocol
that	O
is	O
affected	O
by	O
this	O
trojan	O
is	O
:	O
</s>
