<s>
Stoned	B-Application
is	O
a	O
boot	O
sector	O
computer	O
virus	O
created	O
in	O
1987	O
.	O
</s>
<s>
A	O
computer	O
infected	O
with	O
the	O
original	O
version	O
had	O
a	O
one	O
in	O
eight	O
probability	O
that	O
the	O
screen	O
would	O
declare	O
:	O
"	O
Your	B-Application
PC	I-Application
is	I-Application
now	I-Application
Stoned	I-Application
!	I-Application
</s>
<s>
"	O
,	O
a	O
phrase	O
found	O
in	O
infected	O
boot	O
sectors	O
of	O
infected	O
floppy	B-Device
disks	I-Device
and	O
master	B-Device
boot	I-Device
records	I-Device
of	O
infected	O
hard	B-Device
disks	I-Device
,	O
along	O
with	O
the	O
phrase	O
"	O
Legalise	O
Marijuana	O
"	O
.	O
</s>
<s>
The	O
original	O
"	O
Your	O
PC	O
is	O
now	O
stoned	B-Application
.	O
</s>
<s>
This	O
initial	O
version	O
appears	O
to	O
have	O
been	O
written	O
by	O
someone	O
with	O
experience	O
only	O
with	O
IBM	B-Device
PC	I-Device
360KB	O
floppy	B-Device
drives	I-Device
,	O
as	O
it	O
misbehaves	O
on	O
the	O
IBM	B-Operating_System
AT	I-Operating_System
1.2MB	O
floppy	B-Device
,	O
or	O
on	O
systems	O
with	O
more	O
than	O
96	O
files	O
in	O
the	O
root	O
directory	O
.	O
</s>
<s>
On	O
many	O
IBM	B-Device
PC	I-Device
clones	O
at	O
the	O
time	O
,	O
boot	O
times	O
could	O
vary	O
,	O
so	O
the	O
message	O
would	O
display	O
randomly	O
(	O
1	O
time	O
in	O
8	O
)	O
.	O
</s>
<s>
On	O
some	O
IBM	B-Device
PC	I-Device
compatible	O
machines	O
or	O
on	O
original	O
IBM	B-Device
PC	I-Device
computers	O
,	O
the	O
boot	O
time	O
was	O
constant	O
,	O
so	O
an	O
infected	O
computer	O
would	O
either	O
never	O
display	O
the	O
message	O
or	O
always	O
display	O
the	O
message	O
.	O
</s>
<s>
An	O
infected	O
computer	O
with	O
a	O
360K	B-Device
disk	O
and	O
a	O
20MB	O
or	O
less	O
hard	B-Device
disk	I-Device
,	O
which	O
never	O
displayed	O
the	O
message	O
was	O
one	O
of	O
the	O
first	O
examples	O
of	O
an	O
asymptomatic	O
virus	O
carrier	O
,	O
which	O
would	O
work	O
with	O
no	O
impediment	O
to	O
its	O
function	O
,	O
but	O
which	O
would	O
infect	O
any	O
disks	O
inserted	O
into	O
it	O
.	O
</s>
<s>
On	O
hard	B-Device
disks	I-Device
,	O
the	O
original	O
master	B-Device
boot	I-Device
record	I-Device
is	O
moved	O
to	O
cylinder	O
0	O
,	O
head	O
0	O
,	O
sector	O
7	O
.	O
</s>
<s>
On	O
floppy	B-Device
disks	I-Device
,	O
the	O
original	O
boot	O
sector	O
is	O
moved	O
to	O
cylinder	O
0	O
,	O
head	O
1	O
,	O
sector	O
3	O
,	O
which	O
is	O
the	O
last	O
directory	O
sector	O
on	O
360kB	O
disks	O
.	O
</s>
<s>
The	O
PC	O
was	O
typically	O
infected	O
by	O
booting	O
from	O
an	O
infected	O
diskette	B-Device
.	O
</s>
<s>
Computers	O
,	O
at	O
the	O
time	O
,	O
would	O
default	O
to	O
booting	O
from	O
the	O
A	O
:	O
diskette	B-Device
drive	O
if	O
it	O
had	O
a	O
diskette	B-Device
.	O
</s>
<s>
The	O
virus	O
was	O
spread	O
when	O
a	O
floppy	B-Device
diskette	I-Device
was	O
accessed	O
with	O
an	O
infected	O
computer	O
.	O
</s>
<s>
That	O
diskette	B-Device
was	O
now	O
,	O
itself	O
,	O
a	O
source	O
for	O
further	O
spread	O
of	O
the	O
virus	O
.	O
</s>
<s>
This	O
was	O
much	O
like	O
a	O
recessive	O
gene	O
-	O
difficult	O
to	O
eliminate	O
-	O
because	O
a	O
user	O
could	O
have	O
any	O
number	O
of	O
infected	O
diskettes	B-Device
and	O
yet	O
not	O
have	O
their	O
systems	O
infected	O
with	O
the	O
virus	O
unless	O
they	O
inadvertently	O
boot	O
from	O
an	O
infected	O
diskette	B-Device
.	O
</s>
<s>
Cleaning	O
the	O
computer	O
without	O
cleaning	O
all	O
diskettes	B-Device
left	O
the	O
user	O
susceptible	O
to	O
a	O
repeat	O
infection	O
.	O
</s>
<s>
The	O
method	O
also	O
furthered	O
the	O
spread	O
of	O
the	O
virus	O
in	O
that	O
borrowed	O
diskettes	B-Device
,	O
if	O
placed	O
into	O
the	O
system	O
,	O
were	O
now	O
able	O
to	O
carry	O
the	O
virus	O
to	O
a	O
new	O
host	O
.	O
</s>
<s>
Many	O
variants	O
of	O
Stoned	B-Application
circulated	O
,	O
some	O
only	O
with	O
different	O
messages	O
.	O
</s>
<s>
Manitoba	O
has	O
no	O
activation	O
routine	O
and	O
does	O
not	O
store	O
the	O
original	O
boot	O
sector	O
on	O
floppies	B-Device
;	O
Manitoba	O
simply	O
overwrites	O
the	O
original	O
boot	O
sector	O
.	O
</s>
<s>
2.88MB	O
EHD	O
floppies	B-Device
are	O
corrupted	O
by	O
the	O
virus	O
.	O
</s>
<s>
A	O
variant	O
of	O
Stoned	B-Application
was	O
called	O
Flame	O
(	O
later	O
unrelated	O
sophisticated	O
malware	O
was	O
given	O
the	O
same	O
name	O
)	O
.	O
</s>
<s>
The	O
early	O
Flame	O
uses	O
1	O
kB	O
of	O
DOS	B-Device
memory	O
.	O
</s>
<s>
It	O
stores	O
the	O
original	O
boot	O
sector	O
or	O
master	B-Device
boot	I-Device
record	I-Device
at	O
cylinder	O
25	O
,	O
head	O
1	O
,	O
sector	O
1	O
regardless	O
of	O
the	O
media	O
.	O
</s>
<s>
When	O
the	O
month	O
changes	O
,	O
Flame	O
displays	O
colored	O
flames	O
on	O
the	O
screen	O
and	O
overwrites	O
the	O
master	B-Device
boot	I-Device
record	I-Device
.	O
</s>
<s>
On	O
hard	B-Device
disks	I-Device
,	O
the	O
original	O
master	B-Device
boot	I-Device
record	I-Device
is	O
moved	O
to	O
cylinder	O
0	O
,	O
head	O
0	O
,	O
sector	O
9	O
.	O
</s>
<s>
A	O
Medion	O
press	O
release	O
explained	O
that	O
the	O
virus	O
was	O
not	O
really	O
present	O
;	O
rather	O
,	O
it	O
was	O
a	O
spurious	O
warning	O
caused	O
by	O
a	O
bug	O
in	O
the	O
pre-installed	O
antivirus	B-Application
software	I-Application
,	O
Bullguard	O
.	O
</s>
<s>
On	O
15	O
May	O
2014	O
,	O
the	O
signature	O
of	O
the	O
Stoned	B-Application
virus	I-Application
was	O
inserted	O
into	O
the	O
bitcoin	B-Protocol
blockchain	B-Application
.	O
</s>
<s>
This	O
caused	O
Microsoft	B-Application
Security	I-Application
Essentials	I-Application
to	O
recognize	O
copies	O
of	O
the	O
blockchain	B-Application
as	O
the	O
virus	O
,	O
prompting	O
it	O
to	O
remove	O
the	O
file	O
in	O
question	O
,	O
and	O
subsequently	O
forcing	O
the	O
node	O
to	O
reload	O
the	O
block	B-Application
chain	I-Application
from	O
that	O
point	O
,	O
continuing	O
the	O
cycle	O
.	O
</s>
<s>
Only	O
the	O
signature	O
of	O
the	O
virus	O
had	O
been	O
inserted	O
into	O
the	O
blockchain	B-Application
;	O
the	O
virus	O
itself	O
was	O
not	O
there	O
,	O
and	O
if	O
it	O
were	O
,	O
it	O
would	O
not	O
be	O
able	O
to	O
function	O
.	O
</s>
<s>
The	O
situation	O
was	O
averted	O
shortly	O
thereafter	O
,	O
when	O
Microsoft	O
prevented	O
the	O
blockchain	B-Application
from	O
being	O
recognized	O
as	O
Stoned	B-Application
.	O
</s>
<s>
Microsoft	B-Application
Security	I-Application
Essentials	I-Application
did	O
not	O
lose	O
the	O
ability	O
to	O
detect	O
a	O
real	O
instance	O
of	O
Stoned	B-Application
.	O
</s>
