<s>
OSX.FlashBack	O
,	O
also	O
known	O
as	O
the	O
Flashback	B-Application
Trojan	I-Application
,	O
Fakeflash	B-Application
,	O
or	O
Trojan	B-Application
BackDoor.Flashback	I-Application
,	O
is	O
a	O
Trojan	O
horse	O
affecting	O
personal	O
computer	O
systems	O
running	O
Mac	B-Device
OS	I-Device
X	I-Device
.	O
</s>
<s>
The	O
first	O
variant	O
of	O
Flashback	B-Application
was	O
discovered	O
by	O
antivirus	O
company	O
Intego	O
in	O
September	O
2011	O
.	O
</s>
<s>
Web	O
,	O
a	O
modified	O
version	O
of	O
the	O
"	O
BackDoor.Flashback.39	B-Application
"	O
variant	O
of	O
the	O
Flashback	B-Application
Trojan	I-Application
had	O
infected	O
over	O
600,000	O
Mac	O
computers	O
,	O
forming	O
a	O
botnet	B-Architecture
that	O
included	O
274	O
bots	O
located	O
in	O
Cupertino	O
,	O
California	O
.	O
</s>
<s>
The	O
original	O
variant	O
used	O
a	O
fake	O
installer	O
of	O
Adobe	B-Operating_System
Flash	I-Operating_System
Player	I-Operating_System
to	O
install	O
the	O
malware	O
,	O
hence	O
the	O
name	O
"	O
Flashback	B-Application
"	O
.	O
</s>
<s>
A	O
later	O
variant	O
targeted	O
a	O
Java	B-Language
vulnerability	O
on	O
Mac	B-Device
OS	I-Device
X	I-Device
.	O
</s>
<s>
The	O
system	O
was	O
infected	O
after	O
the	O
user	O
was	O
redirected	O
to	O
a	O
compromised	O
bogus	O
site	O
,	O
where	O
JavaScript	B-Language
code	O
caused	O
an	O
applet	B-Language
containing	O
an	O
exploit	O
to	O
load	O
.	O
</s>
<s>
Oracle	B-Application
,	O
the	O
company	O
that	O
develops	O
Java	B-Language
,	O
fixed	O
the	O
vulnerability	O
exploited	O
to	O
install	O
Flashback	B-Application
on	O
February	O
14	O
,	O
2012	O
.	O
</s>
<s>
However	O
,	O
at	O
the	O
time	O
of	O
Flashback	B-Application
's	O
release	O
,	O
Apple	O
maintained	O
the	O
Mac	B-Device
OS	I-Device
X	I-Device
version	O
of	O
Java	B-Language
and	O
did	O
not	O
release	O
an	O
update	O
containing	O
the	O
fix	O
until	O
April	O
3	O
,	O
2012	O
,	O
after	O
the	O
flaw	O
had	O
already	O
been	O
exploited	O
to	O
install	O
Flashback	B-Application
on	O
600,000	O
Macs	O
.	O
</s>
<s>
On	O
April	O
12	O
,	O
2015	O
,	O
the	O
company	O
issued	O
a	O
further	O
update	O
to	O
remove	O
the	O
most	O
common	O
Flashback	B-Application
variants	O
.	O
</s>
<s>
The	O
updated	O
Java	B-Language
release	O
was	O
only	O
made	O
available	O
for	O
Mac	B-Application
OS	I-Application
X	I-Application
Lion	I-Application
and	O
Mac	B-Device
OS	I-Device
X	I-Device
Snow	I-Device
Leopard	I-Device
;	O
the	O
removal	O
utility	O
was	O
released	O
for	O
Intel	O
versions	O
of	O
Mac	B-Application
OS	I-Application
X	I-Application
Leopard	I-Application
in	O
addition	O
to	O
the	O
two	O
newer	O
operating	O
systems	O
.	O
</s>
<s>
Users	O
of	O
older	O
operating	O
systems	O
were	O
advised	O
to	O
disable	O
Java	B-Language
.	O
</s>
<s>
There	O
are	O
also	O
some	O
third	O
party	O
programs	O
to	O
detect	O
and	O
remove	O
the	O
Flashback	B-Application
trojan	I-Application
.	O
</s>
<s>
Apple	O
worked	O
on	O
a	O
new	O
process	O
that	O
would	O
eventually	O
lead	O
to	O
a	O
release	O
of	O
a	O
Java	B-Language
Runtime	O
Environment	O
(	O
JRE	O
)	O
for	O
Mac	B-Device
OS	I-Device
X	I-Device
at	O
the	O
same	O
time	O
it	O
would	O
be	O
available	O
for	O
Windows	O
,	O
Linux	O
,	O
and	O
Solaris	O
users	O
.	O
</s>
<s>
As	O
of	O
January	O
9	O
,	O
2014	O
,	O
about	O
22,000	O
Macs	O
were	O
still	O
infected	O
with	O
the	O
Flashback	B-Application
trojan	I-Application
.	O
</s>
