<s>
XcodeGhost	B-Application
(	O
and	O
variant	O
XcodeGhost	B-Application
S	O
)	O
are	O
modified	O
versions	O
of	O
Apple	O
's	O
Xcode	B-Operating_System
development	O
environment	O
that	O
are	O
considered	O
malware	O
.	O
</s>
<s>
Security	O
firm	O
Palo	O
Alto	O
Networks	O
surmised	O
that	O
because	O
network	O
speeds	O
were	O
slower	O
in	O
China	O
,	O
developers	O
in	O
the	O
country	O
looked	O
for	O
local	O
copies	O
of	O
the	O
Apple	B-Operating_System
Xcode	I-Operating_System
development	O
environment	O
,	O
and	O
encountered	O
altered	O
versions	O
that	O
had	O
been	O
posted	O
on	O
domestic	O
web	O
sites	O
.	O
</s>
<s>
Even	O
two	O
months	O
after	O
the	O
initial	O
reports	O
,	O
security	O
firm	O
FireEye	O
reported	O
that	O
hundreds	O
of	O
enterprises	O
were	O
still	O
using	O
infected	O
apps	O
and	O
that	O
XcodeGhost	B-Application
remained	O
"	O
a	O
persistent	O
security	O
risk	O
"	O
.	O
</s>
<s>
The	O
firm	O
also	O
identified	O
a	O
new	O
variant	O
of	O
the	O
malware	O
and	O
dubbed	O
it	O
XcodeGhost	B-Application
S	O
;	O
among	O
the	O
apps	O
that	O
were	O
infected	O
were	O
the	O
popular	O
messaging	O
app	O
WeChat	B-Application
and	O
a	O
Netease	O
app	O
Music	O
163	O
.	O
</s>
<s>
On	O
September	O
16	O
,	O
2015	O
,	O
a	O
Chinese	O
iOS	O
developer	O
mentioned	O
on	O
the	O
social	O
network	O
Sina	B-Protocol
Weibo	I-Protocol
that	O
a	O
malware	O
in	O
Xcode	B-Operating_System
injects	O
third	O
party	O
code	O
into	O
apps	O
compiled	O
with	O
it	O
.	O
</s>
<s>
Alibaba	O
researchers	O
then	O
published	O
detailed	O
information	O
on	O
the	O
malware	O
and	O
called	O
it	O
XcodeGhost	B-Application
.	O
</s>
<s>
Because	O
of	O
the	O
slow	B-Application
download	I-Application
speed	I-Application
from	O
Apple	O
servers	O
,	O
Chinese	O
iOS	O
developers	O
would	O
download	O
Xcode	B-Operating_System
from	O
third	O
party	O
websites	O
,	O
such	O
as	O
Baidu	B-Application
Yun	O
(	O
now	O
called	O
Baidu	B-Application
WangPan	O
)	O
,	O
a	O
cloud	O
storage	O
service	O
hosted	O
by	O
Baidu	B-Application
,	O
or	O
get	O
copies	O
from	O
co-workers	O
.	O
</s>
<s>
The	O
novelty	O
of	O
this	O
attack	O
is	O
the	O
modification	O
of	O
the	O
Xcode	B-Operating_System
compiler	O
.	O
</s>
<s>
According	O
to	O
documents	O
leaked	O
by	O
Edward	O
Snowden	O
,	O
CIA	O
security	O
researchers	O
from	O
Sandia	O
National	O
Laboratories	O
claimed	O
that	O
they	O
"	O
had	O
created	O
a	O
modified	O
version	O
of	O
Apple	O
’s	O
proprietary	O
software	O
development	O
tool	O
,	O
Xcode	B-Operating_System
,	O
which	O
could	O
sneak	O
surveillance	O
backdoors	O
into	O
any	O
apps	O
or	O
programs	O
created	O
using	O
the	O
tool.	O
"	O
</s>
<s>
Known	O
versions	O
of	O
XcodeGhost	B-Application
add	O
extra	O
files	O
to	O
the	O
original	O
Xcode	B-Operating_System
application	O
:	O
</s>
<s>
XcodeGhost	B-Application
also	O
modified	O
the	O
linker	B-Application
to	O
link	O
the	O
malicious	O
files	O
into	O
the	O
compiled	O
app	O
.	O
</s>
<s>
This	O
step	O
is	O
reported	O
on	O
the	O
compiling	O
log	O
but	O
not	O
on	O
the	O
Xcode	B-Operating_System
IDE	B-Application
.	O
</s>
<s>
Both	O
iOS	O
and	O
OS	O
X	O
apps	O
are	O
vulnerable	O
to	O
XcodeGhost	B-Application
.	O
</s>
<s>
XcodeGhost	B-Application
compromised	O
the	O
CoreServices	O
layer	O
,	O
which	O
contains	O
highly	O
used	O
features	O
and	O
frameworks	O
used	O
by	O
the	O
app	O
.	O
</s>
<s>
When	O
a	O
developer	O
compiles	O
their	O
application	O
with	O
a	O
compromised	O
version	O
of	O
Xcode	B-Operating_System
,	O
the	O
malicious	O
CoreServices	O
are	O
automatically	O
integrated	O
into	O
the	O
app	O
without	O
the	O
developer	O
's	O
knowledge	O
.	O
</s>
<s>
XcodeGhost	B-Application
can	O
be	O
remotely	O
controlled	O
via	O
commands	O
sent	O
by	O
an	O
attacker	O
from	O
a	O
Command	O
and	O
control	O
server	O
through	O
HTTP	O
.	O
</s>
<s>
This	O
data	O
is	O
encrypted	O
using	O
the	O
DES	B-Algorithm
algorithm	O
in	O
ECB	O
mode	O
.	O
</s>
<s>
When	O
the	O
infected	O
app	O
is	O
launched	O
,	O
either	O
by	O
using	O
an	O
iPhone	O
or	O
the	O
simulator	O
inside	O
Xcode	B-Operating_System
,	O
XcodeGhost	B-Application
will	O
automatically	O
collect	O
device	O
information	O
such	O
as	O
:	O
</s>
<s>
The	O
server	O
differs	O
from	O
version	O
to	O
version	O
of	O
XcodeGhost	B-Application
;	O
Palo	O
Alto	O
Networks	O
was	O
able	O
to	O
find	O
three	O
server	O
URLs	O
:	O
</s>
<s>
XcodeGhost	B-Application
is	O
also	O
able	O
,	O
each	O
time	O
an	O
infected	O
app	O
is	O
launched	O
,	O
to	O
store	O
the	O
data	O
written	O
in	O
the	O
iOS	O
clipboard	O
.	O
</s>
<s>
XcodeGhost	B-Application
is	O
also	O
able	O
to	O
open	O
specific	O
URLs	O
when	O
the	O
infected	O
app	O
is	O
launched	O
.	O
</s>
<s>
In	O
its	O
current	O
known	O
version	O
XcodeGhost	B-Application
cannot	O
prompt	O
alert	O
dialogs	O
on	O
the	O
user	O
device	O
.	O
</s>
<s>
Popular	O
apps	O
used	O
all	O
over	O
the	O
world	O
were	O
also	O
infected	O
such	O
as	O
WeChat	B-Application
,	O
a	O
popular	O
instant	O
messaging	O
app	O
,	O
CamScanner	B-Application
,	O
an	O
app	O
to	O
scan	O
document	O
using	O
the	O
smartphone	O
camera	O
or	O
WinZip	B-Application
.	O
</s>
<s>
Pangu	B-Operating_System
Team	I-Operating_System
claimed	O
that	O
they	O
counted	O
3,418	O
infected	O
apps	O
.	O
</s>
<s>
Since	O
the	O
article	O
of	O
Alibaba	O
and	O
Palo	O
Alto	O
Networks	O
,	O
Amazon	B-Application
took	O
down	O
all	O
the	O
servers	O
that	O
were	O
used	O
by	O
XcodeGhost	B-Application
.	O
</s>
<s>
Baidu	B-Application
also	O
removed	O
all	O
malicious	O
Xcode	B-Operating_System
installers	O
from	O
its	O
cloud	O
storage	O
service	O
.	O
</s>
<s>
On	O
September	O
18	O
,	O
2015	O
Apple	O
admitted	O
the	O
existence	O
of	O
the	O
malware	O
and	O
began	O
asking	O
all	O
developers	O
with	O
compromised	O
apps	O
to	O
compile	O
their	O
apps	O
with	O
a	O
clean	O
version	O
of	O
Xcode	B-Operating_System
before	O
submitting	O
them	O
for	O
review	O
again	O
.	O
</s>
<s>
Pangu	B-Operating_System
Team	I-Operating_System
released	O
a	O
tool	O
to	O
detect	O
infected	O
apps	O
on	O
a	O
device	O
,	O
but	O
like	O
other	O
antivirus	O
apps	O
it	O
wo	O
n't	O
run	O
on	O
a	O
device	O
that	O
has	O
n't	O
been	O
jailbroken	B-Application
.	O
</s>
<s>
Apple	O
advises	O
Xcode	B-Operating_System
developers	O
to	O
verify	O
their	O
version	O
of	O
Xcode	B-Operating_System
and	O
to	O
always	O
have	O
Gatekeeper	B-Operating_System
activated	O
on	O
their	O
machine	O
.	O
</s>
