<s>
The	O
RSPlug	B-Application
Trojan	O
horse	O
,	O
a	O
form	O
of	O
DNSChanger	B-Application
,	O
is	O
malware	O
targeting	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
operating	O
system	O
.	O
</s>
<s>
The	O
first	O
incarnation	O
of	O
the	O
trojan	O
,	O
OSX.RSPlug.A	O
,	O
was	O
discovered	O
on	O
October	O
30	O
,	O
2007	O
by	O
Mac	O
security	O
researchers	O
at	O
Intego	O
.	O
</s>
<s>
Several	O
variants	O
of	O
the	O
RSPlug	B-Application
trojan	O
were	O
found	O
primarily	O
on	O
pornographic	O
sites	O
disguised	O
as	O
video	O
codecs	O
,	O
and	O
some	O
variants	O
were	O
spotted	O
on	O
sites	O
offering	O
game	O
downloads	O
.	O
</s>
<s>
When	O
OSX.RSPlug.A	O
was	O
installed	O
,	O
the	O
system	O
's	O
DNS	B-Protocol
settings	O
were	O
changed	O
to	O
redirect	O
web	O
browsing	O
to	O
phishing	O
web	O
sites	O
,	O
or	O
to	O
web	O
pages	O
displaying	O
ads	O
for	O
other	O
pornographic	O
web	O
sites	O
.	O
</s>
<s>
There	O
is	O
also	O
a	O
version	O
of	O
the	O
OSX.RSPlug	B-Application
Trojan	I-Application
which	O
targets	O
the	O
Windows	O
platform	O
,	O
and	O
it	O
was	O
this	O
version	O
that	O
led	O
a	O
technical	O
manager	O
at	O
F-Secure	O
to	O
suggest	O
that	O
the	O
group	O
behind	O
the	O
DNS-changing	O
Mac	O
Trojan	O
is	O
the	O
same	O
group	O
behind	O
the	O
Zlob	B-Application
trojan	I-Application
.	O
</s>
<s>
However	O
,	O
Intego	O
noted	O
that	O
those	O
behind	O
the	O
RSPlug	B-Application
Trojan	O
horse	O
stopped	O
their	O
activities	O
before	O
those	O
controlling	O
Windows	O
malware	O
,	O
and	O
that	O
it	O
is	O
likely	O
that	O
these	O
were	O
not	O
the	O
same	O
people	O
.	O
</s>
<s>
The	O
FBI	O
estimated	O
that	O
more	O
than	O
four	O
million	O
computers	O
in	O
over	O
100	O
countries	O
were	O
infected	O
by	O
DNSChanger	B-Application
.	O
</s>
<s>
One	O
variant	O
of	O
DNSChanger	B-Application
was	O
the	O
RSPlug	B-Application
Trojan	O
horse	O
,	O
which	O
spawned	O
a	O
number	O
of	O
other	O
variants	O
and	O
infected	O
many	O
Macs	O
.	O
</s>
