<s>
Staog	B-Application
was	O
the	O
first	O
computer	O
virus	O
written	O
for	O
the	O
Linux	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
Staog	B-Application
was	O
able	O
to	O
infect	O
Linux	B-Application
despite	O
its	O
security-oriented	O
design	O
which	O
requires	O
users	O
and	O
programs	B-Application
to	O
log	O
in	O
as	O
root	B-Application
before	O
any	O
drastic	O
operations	O
can	O
be	O
taken	O
.	O
</s>
<s>
It	O
worked	O
by	O
exploiting	O
some	O
kernel	B-Operating_System
vulnerabilities	O
to	O
stay	O
resident	O
.	O
</s>
<s>
Then	O
,	O
it	O
would	O
infect	O
executed	O
binaries	B-Application
.	O
</s>
<s>
Since	O
it	O
relied	O
on	O
fundamental	O
bugs	B-Error_Name
,	O
software	O
upgrades	O
made	O
systems	O
immune	O
to	O
Staog	B-Application
.	O
</s>
<s>
Staog	B-Application
was	O
written	O
in	O
assembly	B-Language
language	I-Language
by	O
the	O
hacker	O
group	O
VLAD	O
.	O
</s>
