<s>
macOS	B-Application
malware	I-Application
includes	O
viruses	O
,	O
trojan	O
horses	O
,	O
worms	O
and	O
other	O
types	O
of	O
malware	O
that	O
affect	O
macOS	B-Application
,	O
Apple	O
's	O
current	O
operating	B-General_Concept
system	I-General_Concept
for	O
Macintosh	B-Device
computers	I-Device
.	O
</s>
<s>
macOS	B-Application
(	O
previously	O
Mac	B-Application
OS	I-Application
X	O
and	O
OS	O
X	O
)	O
is	O
said	O
to	O
rarely	O
suffer	O
malware	O
or	O
virus	O
attacks	O
,	O
and	O
has	O
been	O
considered	O
less	O
vulnerable	O
than	O
Windows	B-Application
.	O
</s>
<s>
There	O
is	O
a	O
frequent	O
release	O
of	O
system	B-Application
software	I-Application
updates	O
to	O
resolve	O
vulnerabilities	O
.	O
</s>
<s>
Early	O
examples	O
of	O
macOS	B-Application
malware	I-Application
include	O
MP3Concept	B-Operating_System
(	O
discovered	O
2004	O
,	O
a	O
benign	O
proof	O
of	O
concept	O
for	O
a	O
trojan	O
horse	O
)	O
,	O
Leap	B-Application
(	O
discovered	O
in	O
2006	O
,	O
also	O
known	O
as	O
Oompa-Loompa	O
)	O
and	O
RSPlug	B-Application
(	O
discovered	O
in	O
2007	O
)	O
.	O
</s>
<s>
An	O
application	O
called	O
MacSweeper	B-Application
(	O
2009	O
)	O
misled	O
users	O
about	O
malware	O
threats	O
in	O
order	O
to	O
take	O
their	O
credit	O
card	O
details	O
.	O
</s>
<s>
In	O
2012	O
,	O
a	O
worm	O
known	O
as	O
Flashback	B-Application
appeared	O
.	O
</s>
<s>
Initially	O
,	O
it	O
infected	O
computers	O
through	O
fake	O
Adobe	B-Operating_System
Flash	I-Operating_System
Player	I-Operating_System
install	O
prompts	O
,	O
but	O
it	O
later	O
exploited	O
a	O
vulnerability	O
in	O
Java	B-Language
to	O
install	O
itself	O
without	O
user	O
intervention	O
.	O
</s>
<s>
The	O
malware	O
forced	O
Oracle	O
and	O
Apple	O
to	O
release	O
bug	O
fixes	O
for	O
Java	B-Language
to	O
remove	O
the	O
vulnerability	O
.	O
</s>
<s>
Bit9	O
and	O
Carbon	O
Black	O
reported	O
at	O
the	O
end	O
of	O
2015	O
that	O
Mac	B-Application
malware	I-Application
had	O
been	O
more	O
prolific	O
that	O
year	O
than	O
ever	O
before	O
,	O
including	O
:	O
</s>
<s>
A	O
trojan	O
known	O
as	O
Keydnap	B-Application
first	O
appeared	O
in	O
2016	O
,	O
which	O
placed	O
a	O
backdoor	O
on	O
victims	O
 '	O
computers	O
.	O
</s>
<s>
Adware	O
is	O
also	O
a	O
problem	O
on	O
the	O
Mac	B-Device
,	O
with	O
software	O
like	O
Genieo	B-Application
,	O
which	O
was	O
released	O
in	O
2009	O
,	O
inserting	O
ads	O
into	O
webpages	O
and	O
changing	O
users	O
 '	O
homepage	O
and	O
search	O
engine	O
.	O
</s>
<s>
Malware	O
has	O
also	O
been	O
spread	O
on	O
Macs	B-Device
through	O
Microsoft	B-Application
Word	I-Application
macros	O
.	O
</s>
<s>
In	O
March	O
2016	O
Apple	O
shut	O
down	O
the	O
first	O
ransomware	O
attack	O
targeted	O
against	O
Mac	B-Device
users	O
,	O
encrypting	O
the	O
users	O
 '	O
confidential	O
information	O
.	O
</s>
<s>
After	O
completing	O
the	O
encryption	O
process	O
,	O
KeRanger	O
demanded	O
that	O
victims	O
pay	O
one	O
bitcoin	B-Protocol
(	O
about	O
at	O
the	O
time	O
,	O
about	O
as	O
of	O
December	O
25	O
,	O
2022	O
)	O
for	O
the	O
user	O
to	O
recover	O
their	O
credentials	O
.	O
</s>
