<s>
The	O
Oompa-Loompa	O
malware	O
,	O
also	O
called	O
OSX/Oomp	O
-A	O
or	O
Leap.A	B-Application
,	O
is	O
an	O
application-infecting	O
,	O
LAN-spreading	O
worm	O
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
discovered	O
by	O
the	O
Apple	O
security	O
firm	O
Intego	O
on	O
February	O
14	O
,	O
2006	O
.	O
</s>
<s>
Leap	B-Application
cannot	O
spread	O
over	O
the	O
Internet	O
,	O
and	O
can	O
only	O
spread	O
over	O
a	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
reachable	O
using	O
the	O
Bonjour	B-Application
protocol	I-Application
.	O
</s>
<s>
On	O
most	O
networks	O
this	O
limits	O
it	O
to	O
a	O
single	O
IP	B-Protocol
subnet	I-Protocol
.	O
</s>
<s>
The	O
Leap	B-Application
worm	O
is	O
delivered	O
over	O
the	O
iChat	B-Protocol
instant	B-Application
messaging	I-Application
program	O
as	O
a	O
gzip-compressed	O
tar	B-Application
file	I-Application
called	O
.	O
</s>
<s>
For	O
the	O
worm	O
to	O
take	O
effect	O
,	O
the	O
user	O
must	O
manually	O
invoke	O
it	O
by	O
opening	O
the	O
tar	B-Application
file	I-Application
and	O
then	O
running	O
the	O
disguised	O
executable	O
within	O
.	O
</s>
<s>
Leap	B-Application
only	O
infects	O
Cocoa	B-Operating_System
applications	O
,	O
and	O
it	O
does	O
not	O
infect	O
applications	O
owned	O
by	O
the	O
system	O
(	O
including	O
the	O
apps	O
that	O
come	O
pre-installed	O
on	O
a	O
new	O
machine	O
)	O
,	O
but	O
only	O
apps	O
owned	O
by	O
the	O
user	O
who	O
is	O
currently	O
logged	O
in	O
.	O
</s>
<s>
When	O
an	O
infected	O
app	O
is	O
launched	O
,	O
Leap	B-Application
tries	O
to	O
infect	O
the	O
four	O
most	O
recently	O
used	O
applications	O
.	O
</s>
<s>
Once	O
activated	O
,	O
Leap	B-Application
then	O
attempts	O
to	O
spread	O
itself	O
via	O
the	O
user	O
's	O
iChat	B-Protocol
Bonjour	B-Application
buddy	O
list	O
.	O
</s>
<s>
It	O
does	O
not	O
spread	O
using	O
the	O
main	O
iChat	B-Protocol
buddy	O
list	O
,	O
nor	O
over	O
XMPP	B-Protocol
.	O
</s>
<s>
(	O
By	O
default	O
,	O
iChat	B-Protocol
does	O
not	O
use	O
Bonjour	B-Application
and	O
thus	O
cannot	O
transmit	O
this	O
worm	O
.	O
)	O
</s>
<s>
Leap	B-Application
does	O
not	O
delete	O
data	O
,	O
spy	O
on	O
the	O
system	O
,	O
or	O
take	O
control	O
of	O
it	O
,	O
but	O
it	O
does	O
have	O
one	O
harmful	O
effect	O
:	O
due	O
to	O
a	O
bug	O
in	O
the	O
worm	O
itself	O
,	O
an	O
infected	O
application	O
will	O
not	O
launch	O
.	O
</s>
<s>
Recovering	O
after	O
a	O
Leap	B-Application
infection	O
involves	O
deleting	O
the	O
worm	O
files	O
and	O
replacing	O
infected	O
applications	O
with	O
fresh	O
copies	O
.	O
</s>
