<s>
Antivirus	B-Application
software	I-Application
(	O
abbreviated	O
to	O
AV	B-Application
software	I-Application
)	O
,	O
also	O
known	O
as	O
anti-malware	B-Application
,	O
is	O
a	O
computer	B-Application
program	I-Application
used	O
to	O
prevent	O
,	O
detect	O
,	O
and	O
remove	O
malware	O
.	O
</s>
<s>
Antivirus	B-Application
software	I-Application
was	O
originally	O
developed	O
to	O
detect	O
and	O
remove	O
computer	O
viruses	O
,	O
hence	O
the	O
name	O
.	O
</s>
<s>
However	O
,	O
with	O
the	O
proliferation	O
of	O
other	O
malware	O
,	O
antivirus	B-Application
software	I-Application
started	O
to	O
protect	O
against	O
other	O
computer	O
threats	O
.	O
</s>
<s>
Although	O
the	O
roots	O
of	O
the	O
computer	O
virus	O
date	O
back	O
as	O
early	O
as	O
1949	O
,	O
when	O
the	O
Hungarian	O
scientist	O
John	O
von	O
Neumann	O
published	O
the	O
"	O
Theory	O
of	O
self-reproducing	O
automata	O
"	O
,	O
the	O
first	O
known	O
computer	O
virus	O
appeared	O
in	O
1971	O
and	O
was	O
dubbed	O
the	O
"	O
Creeper	B-Application
virus	I-Application
"	O
.	O
</s>
<s>
This	O
computer	O
virus	O
infected	O
Digital	O
Equipment	O
Corporation	O
's	O
(	O
DEC	O
)	O
PDP-10	B-Device
mainframe	O
computers	O
running	O
the	O
TENEX	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
Creeper	B-Application
virus	I-Application
was	O
eventually	O
deleted	O
by	O
a	O
program	O
created	O
by	O
Ray	O
Tomlinson	O
and	O
known	O
as	O
"	O
The	B-Application
Reaper	I-Application
"	O
.	O
</s>
<s>
Some	O
people	O
consider	O
"	O
The	B-Application
Reaper	I-Application
"	O
the	O
first	O
antivirus	B-Application
software	I-Application
ever	O
written	O
–	O
it	O
may	O
be	O
the	O
case	O
,	O
but	O
it	O
is	O
important	O
to	O
note	O
that	O
the	B-Application
Reaper	I-Application
was	O
actually	O
a	O
virus	O
itself	O
specifically	O
designed	O
to	O
remove	O
the	O
Creeper	B-Application
virus	I-Application
.	O
</s>
<s>
The	O
Creeper	B-Application
virus	I-Application
was	O
followed	O
by	O
several	O
other	O
viruses	O
.	O
</s>
<s>
The	O
first	O
known	O
that	O
appeared	O
"	O
in	O
the	O
wild	O
"	O
was	O
"	O
Elk	O
Cloner	O
"	O
,	O
in	O
1981	O
,	O
which	O
infected	O
Apple	B-Device
II	I-Device
computers	O
.	O
</s>
<s>
Cohen	O
used	O
the	O
term	O
"	O
computer	O
virus	O
"	O
to	O
describe	O
programs	O
that	O
:	O
"	O
affect	O
other	O
computer	B-Application
programs	I-Application
by	O
modifying	O
them	O
in	O
such	O
a	O
way	O
as	O
to	O
include	O
a	O
(	O
possibly	O
evolved	O
)	O
copy	O
of	O
itself.	O
"	O
</s>
<s>
Before	O
internet	O
connectivity	O
was	O
widespread	O
,	O
computer	O
viruses	O
were	O
typically	O
spread	O
by	O
infected	O
floppy	B-Device
disks	I-Device
.	O
</s>
<s>
Antivirus	B-Application
software	I-Application
came	O
into	O
use	O
,	O
but	O
was	O
updated	O
relatively	O
infrequently	O
.	O
</s>
<s>
During	O
this	O
time	O
,	O
virus	B-Application
checkers	I-Application
essentially	O
had	O
to	O
check	O
executable	B-Application
files	I-Application
and	O
the	O
boot	B-Operating_System
sectors	O
of	O
floppy	B-Device
disks	I-Device
and	O
hard	O
disks	O
.	O
</s>
<s>
There	O
are	O
competing	O
claims	O
for	O
the	O
innovator	O
of	O
the	O
first	O
antivirus	B-Application
product	O
.	O
</s>
<s>
In	O
1987	O
,	O
Andreas	O
Lüning	O
and	O
Kai	O
Figge	O
,	O
who	O
founded	O
G	B-Application
Data	I-Application
Software	I-Application
in	O
1985	O
,	O
released	O
their	O
first	O
antivirus	B-Application
product	O
for	O
the	O
Atari	B-Device
ST	I-Device
platform	O
.	O
</s>
<s>
In	O
1987	O
,	O
the	O
Ultimate	O
Virus	B-Application
Killer	I-Application
(	O
UVK	O
)	O
was	O
also	O
released	O
.	O
</s>
<s>
This	O
was	O
the	O
de	O
facto	O
industry	O
standard	O
virus	B-Application
killer	I-Application
for	O
the	O
Atari	B-Device
ST	I-Device
and	O
Atari	B-Device
Falcon	I-Device
,	O
the	O
last	O
version	O
of	O
which	O
(	O
version	O
9.0	O
)	O
was	O
released	O
in	O
April	O
2004	O
.	O
</s>
<s>
In	O
1987	O
,	O
in	O
the	O
United	O
States	O
,	O
John	O
McAfee	O
founded	O
the	O
McAfee	O
company	O
(	O
was	O
part	O
of	O
Intel	O
Security	O
)	O
and	O
,	O
at	O
the	O
end	O
of	O
that	O
year	O
,	O
he	O
released	O
the	O
first	O
version	O
of	O
VirusScan	B-Operating_System
.	O
</s>
<s>
Also	O
in	O
1987	O
(	O
in	O
Czechoslovakia	O
)	O
,	O
Peter	O
Paško	O
,	O
Rudolf	O
Hrubý	O
,	O
and	O
Miroslav	O
Trnka	O
created	O
the	O
first	O
version	O
of	O
NOD	B-Application
antivirus	B-Application
.	O
</s>
<s>
Finally	O
,	O
at	O
the	O
end	O
of	O
1987	O
,	O
the	O
first	O
two	O
heuristic	B-Algorithm
antivirus	B-Application
utilities	O
were	O
released	O
:	O
Flushot	O
Plus	O
by	O
Ross	O
Greenberg	O
and	O
Anti4us	O
by	O
Erwin	O
Lanting	O
.	O
</s>
<s>
In	O
his	O
O'Reilly	O
book	O
,	O
Malicious	O
Mobile	O
Code	O
:	O
Virus	B-Application
Protection	I-Application
for	O
Windows	O
,	O
Roger	O
Grimes	O
described	O
Flushot	O
Plus	O
as	O
"	O
the	O
first	O
holistic	O
program	O
to	O
fight	O
malicious	O
mobile	O
code	O
(	O
MMC	O
)	O
.	O
"	O
</s>
<s>
However	O
,	O
the	O
kind	O
of	O
heuristic	B-Algorithm
used	O
by	O
early	O
AV	O
engines	O
was	O
totally	O
different	O
from	O
those	O
used	O
today	O
.	O
</s>
<s>
The	O
first	O
product	O
with	O
a	O
heuristic	B-Algorithm
engine	O
resembling	O
modern	O
ones	O
was	O
F-PROT	O
in	O
1991	O
.	O
</s>
<s>
Early	O
heuristic	B-Algorithm
engines	O
were	O
based	O
on	O
dividing	O
the	O
binary	O
into	O
different	O
sections	O
:	O
data	O
section	O
,	O
code	O
section	O
(	O
in	O
a	O
legitimate	O
binary	O
,	O
it	O
usually	O
starts	O
always	O
from	O
the	O
same	O
location	O
)	O
.	O
</s>
<s>
This	O
was	O
a	O
very	O
specific	O
pattern	O
,	O
not	O
used	O
at	O
the	O
time	O
by	O
any	O
legitimate	O
software	O
,	O
which	O
represented	O
an	O
elegant	O
heuristic	B-Algorithm
to	O
catch	O
suspicious	O
code	O
.	O
</s>
<s>
Other	O
kinds	O
of	O
more	O
advanced	O
heuristics	B-Algorithm
were	O
later	O
added	O
,	O
such	O
as	O
suspicious	O
section	O
names	O
,	O
incorrect	O
header	O
size	O
,	O
regular	O
expressions	O
,	O
and	O
partial	O
pattern	O
in-memory	O
matching	O
.	O
</s>
<s>
In	O
1988	O
,	O
the	O
growth	O
of	O
antivirus	B-Application
companies	O
continued	O
.	O
</s>
<s>
In	O
Germany	O
,	O
Tjark	O
Auerbach	O
founded	O
Avira	B-Application
(	O
H+BEDV	B-Application
at	O
the	O
time	O
)	O
and	O
released	O
the	O
first	O
version	O
of	O
AntiVir	B-Application
(	O
named	O
"	O
Luke	B-Application
Filewalker	I-Application
"	O
at	O
the	O
time	O
)	O
.	O
</s>
<s>
In	O
Bulgaria	O
,	O
Vesselin	O
Bontchev	O
released	O
his	O
first	O
freeware	O
antivirus	B-Application
program	I-Application
(	O
he	O
later	O
joined	O
FRISK	O
Software	O
)	O
.	O
</s>
<s>
Also	O
Frans	O
Veldman	O
released	O
the	O
first	O
version	O
of	O
ThunderByte	B-Application
Antivirus	I-Application
,	O
also	O
known	O
as	O
TBAV	B-Application
(	O
he	O
sold	O
his	O
company	O
to	O
Norman	O
Safeground	O
in	O
1998	O
)	O
.	O
</s>
<s>
antivirus	B-Application
.	O
</s>
<s>
In	O
June	O
1988	O
,	O
in	O
South	O
Korea	O
,	O
Ahn	O
Cheol-Soo	O
released	O
its	O
first	O
antivirus	B-Application
software	I-Application
,	O
called	O
V1	O
(	O
he	O
founded	O
AhnLab	O
later	O
in	O
1995	O
)	O
.	O
</s>
<s>
Finally	O
,	O
in	O
autumn	O
1988	O
,	O
in	O
the	O
United	O
Kingdom	O
,	O
Alan	O
Solomon	O
founded	O
S&S	O
International	O
and	O
created	O
his	O
Dr.	B-Application
Solomon	I-Application
's	I-Application
Anti-Virus	I-Application
Toolkit	I-Application
(	O
although	O
he	O
launched	O
it	O
commercially	O
only	O
in	O
1991	O
–	O
in	O
1998	O
Solomon	O
's	O
company	O
was	O
acquired	O
by	O
McAfee	O
)	O
.	O
</s>
<s>
In	O
November	O
1988	O
a	O
professor	O
at	O
the	O
Panamerican	O
University	O
in	O
Mexico	O
City	O
named	O
Alejandro	O
E	O
.	O
Carriles	O
copyrighted	O
the	O
first	O
antivirus	B-Application
software	I-Application
in	O
Mexico	O
under	O
the	O
name	O
"	O
Byte	O
Matabichos	O
"	O
(	O
Byte	O
Bugkiller	O
)	O
to	O
help	O
solve	O
the	O
rampant	O
virus	O
infestation	O
among	O
students	O
.	O
</s>
<s>
Also	O
in	O
1988	O
,	O
a	O
mailing	O
list	O
named	O
VIRUS-L	O
was	O
started	O
on	O
the	O
BITNET/EARN	O
network	B-General_Concept
where	O
new	O
viruses	O
and	O
the	O
possibilities	O
of	O
detecting	O
and	O
eliminating	O
viruses	O
were	O
discussed	O
.	O
</s>
<s>
Some	O
members	O
of	O
this	O
mailing	O
list	O
were	O
:	O
Alan	O
Solomon	O
,	O
Eugene	O
Kaspersky	O
(	O
Kaspersky	O
Lab	O
)	O
,	O
Friðrik	O
Skúlason	O
(	O
FRISK	O
Software	O
)	O
,	O
John	O
McAfee	O
(	O
McAfee	O
)	O
,	O
Luis	O
Corrons	O
(	O
Panda	O
Security	O
)	O
,	O
Mikko	O
Hyppönen	O
(	O
F-Secure	O
)	O
,	O
Péter	O
Szőr	O
,	O
Tjark	O
Auerbach	O
(	O
Avira	B-Application
)	O
and	O
Vesselin	O
Bontchev	O
(	O
FRISK	O
Software	O
)	O
.	O
</s>
<s>
In	O
1989	O
,	O
in	O
Iceland	O
,	O
Friðrik	O
Skúlason	O
created	O
the	O
first	O
version	O
of	O
F-PROT	O
Anti-Virus	B-Application
(	O
he	O
founded	O
FRISK	O
Software	O
only	O
in	O
1993	O
)	O
.	O
</s>
<s>
Meanwhile	O
in	O
the	O
United	O
States	O
,	O
Symantec	O
(	O
founded	O
by	O
Gary	O
Hendrix	O
in	O
1982	O
)	O
launched	O
its	O
first	O
Symantec	B-Application
antivirus	I-Application
for	I-Application
Macintosh	I-Application
(	O
SAM	O
)	O
.	O
</s>
<s>
In	O
the	O
end	O
of	O
the	O
1980s	O
,	O
in	O
United	O
Kingdom	O
,	O
Jan	O
Hruska	O
and	O
Peter	O
Lammer	O
founded	O
the	O
security	O
firm	O
Sophos	O
and	O
began	O
producing	O
their	O
first	O
antivirus	B-Application
and	O
encryption	O
products	O
.	O
</s>
<s>
In	O
Hungary	O
,	O
the	O
security	O
researcher	O
Péter	O
Szőr	O
released	O
the	O
first	O
version	O
of	O
Pasteur	O
antivirus	B-Application
.	O
</s>
<s>
In	O
Italy	O
,	O
Gianfranco	O
Tonello	O
created	O
the	O
first	O
version	O
of	O
VirIT	O
eXplorer	O
antivirus	B-Application
,	O
then	O
founded	O
TG	O
Soft	O
one	O
year	O
later	O
.	O
</s>
<s>
In	O
1990	O
,	O
the	O
Computer	O
Antivirus	B-Application
Research	O
Organization	O
(	O
CARO	B-Application
)	O
was	O
founded	O
.	O
</s>
<s>
In	O
1991	O
,	O
CARO	B-Application
released	O
the	O
"	O
Virus	O
Naming	O
Scheme	O
"	O
,	O
originally	O
written	O
by	O
Friðrik	O
Skúlason	O
and	O
Vesselin	O
Bontchev	O
.	O
</s>
<s>
CARO	B-Application
members	O
includes	O
:	O
Alan	O
Solomon	O
,	O
Costin	O
Raiu	O
,	O
Dmitry	O
Gryaznov	O
,	O
Eugene	O
Kaspersky	O
,	O
Friðrik	O
Skúlason	O
,	O
Igor	O
Muttik	O
,	O
Mikko	O
Hyppönen	O
,	O
Morton	O
Swimmer	O
,	O
Nick	O
FitzGerald	O
,	O
Padgett	O
Peterson	O
,	O
Peter	O
Ferrie	O
,	O
Righard	O
Zwienenberg	O
and	O
Vesselin	O
Bontchev	O
.	O
</s>
<s>
In	O
1991	O
,	O
in	O
the	O
United	O
States	O
,	O
Symantec	O
released	O
the	O
first	O
version	O
of	O
Norton	B-Application
AntiVirus	I-Application
.	O
</s>
<s>
In	O
the	O
same	O
year	O
,	O
in	O
the	O
Czech	O
Republic	O
,	O
Jan	O
Gritzbach	O
and	O
Tomáš	O
Hofer	O
founded	O
AVG	B-Application
Technologies	O
(	O
Grisoft	O
at	O
the	O
time	O
)	O
,	O
although	O
they	O
released	O
the	O
first	O
version	O
of	O
their	O
Anti-Virus	B-Application
Guard	O
(	O
AVG	B-Application
)	O
only	O
in	O
1992	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
in	O
Finland	O
,	O
F-Secure	O
(	O
founded	O
in	O
1988	O
by	O
Petri	O
Allas	O
and	O
Risto	O
Siilasmaa	O
–	O
with	O
the	O
name	O
of	O
Data	O
Fellows	O
)	O
released	O
the	O
first	O
version	O
of	O
their	O
antivirus	B-Application
product	O
.	O
</s>
<s>
F-Secure	O
claims	O
to	O
be	O
the	O
first	O
antivirus	B-Application
firm	O
to	O
establish	O
a	O
presence	O
on	O
the	O
World	O
Wide	O
Web	O
.	O
</s>
<s>
In	O
1991	O
,	O
the	O
European	O
Institute	O
for	O
Computer	O
Antivirus	B-Application
Research	O
(	O
EICAR	O
)	O
was	O
founded	O
to	O
further	O
antivirus	B-Application
research	O
and	O
improve	O
development	O
of	O
antivirus	B-Application
software	I-Application
.	O
</s>
<s>
In	O
1996	O
,	O
in	O
Romania	O
,	O
Bitdefender	B-Application
was	O
founded	O
and	O
released	O
the	O
first	O
version	O
of	O
Anti-Virus	B-Application
eXpert	O
(	O
AVX	O
)	O
.	O
</s>
<s>
In	O
1996	O
,	O
there	O
was	O
also	O
the	O
first	O
"	O
in	O
the	O
wild	O
"	O
Linux	B-Application
virus	I-Application
,	O
known	O
as	O
"	O
Staog	B-Application
"	O
.	O
</s>
<s>
In	O
2000	O
,	O
Rainer	O
Link	O
and	O
Howard	O
Fuhs	O
started	O
the	O
first	O
open	O
source	O
antivirus	B-Application
engine	O
,	O
called	O
OpenAntivirus	O
Project	O
.	O
</s>
<s>
In	O
2001	O
,	O
Tomasz	O
Kojm	O
released	O
the	O
first	O
version	O
of	O
ClamAV	B-Application
,	O
the	O
first	O
ever	O
open	O
source	O
antivirus	B-Application
engine	O
to	O
be	O
commercialised	O
.	O
</s>
<s>
In	O
2007	O
,	O
ClamAV	B-Application
was	O
bought	O
by	O
Sourcefire	O
,	O
which	O
in	O
turn	O
was	O
acquired	O
by	O
Cisco	O
Systems	O
in	O
2013	O
.	O
</s>
<s>
In	O
2002	O
,	O
in	O
United	O
Kingdom	O
,	O
Morten	O
Lund	O
and	O
Theis	O
Søndergaard	O
co-founded	O
the	O
antivirus	B-Application
firm	O
BullGuard	O
.	O
</s>
<s>
In	O
2012	O
and	O
2013	O
,	O
antivirus	B-Application
firms	O
reported	O
a	O
new	O
malware	O
samples	O
range	O
from	O
300,000	O
to	O
over	O
500,000	O
per	O
day	O
.	O
</s>
<s>
Over	O
the	O
years	O
it	O
has	O
become	O
necessary	O
for	O
antivirus	B-Application
software	I-Application
to	O
use	O
several	O
different	O
strategies	O
(	O
e.g.	O
</s>
<s>
specific	O
email	O
and	O
network	B-General_Concept
protection	O
or	O
low	O
level	O
modules	O
)	O
and	O
detection	O
algorithms	O
,	O
as	O
well	O
as	O
to	O
check	O
an	O
increasing	O
variety	O
of	O
files	O
,	O
rather	O
than	O
just	O
executables	B-Application
,	O
for	O
several	O
reasons	O
:	O
</s>
<s>
Powerful	O
macros	O
used	O
in	O
word	B-General_Concept
processor	I-General_Concept
applications	O
,	O
such	O
as	O
Microsoft	B-Application
Word	I-Application
,	O
presented	O
a	O
risk	O
.	O
</s>
<s>
The	O
possibility	O
of	O
embedding	O
executable	B-Application
objects	O
inside	O
otherwise	O
non-executable	O
file	O
formats	O
can	O
make	O
opening	O
those	O
files	O
a	O
risk	O
.	O
</s>
<s>
Later	O
email	O
programs	O
,	O
in	O
particular	O
Microsoft	O
's	O
Outlook	B-Application
Express	I-Application
and	O
Outlook	B-Application
,	O
were	O
vulnerable	O
to	O
viruses	O
embedded	O
in	O
the	O
email	O
body	O
itself	O
.	O
</s>
<s>
Because	O
most	O
users	O
are	O
usually	O
connected	O
to	O
the	O
Internet	O
on	O
a	O
continual	O
basis	O
,	O
Jon	O
Oberheide	O
first	O
proposed	O
a	O
Cloud-based	B-Architecture
antivirus	B-Application
design	O
in	O
2008	O
.	O
</s>
<s>
In	O
February	O
2008	O
McAfee	O
Labs	O
added	O
the	O
industry-first	O
cloud-based	B-Architecture
anti-malware	B-Application
functionality	O
to	O
VirusScan	B-Operating_System
under	O
the	O
name	O
Artemis	B-Operating_System
.	O
</s>
<s>
It	O
was	O
tested	O
by	O
AV-Comparatives	O
in	O
February	O
2008	O
and	O
officially	O
unveiled	O
in	O
August	O
2008	O
in	O
McAfee	B-Operating_System
VirusScan	I-Operating_System
.	O
</s>
<s>
Cloud	O
AV	O
created	O
problems	O
for	O
comparative	O
testing	O
of	O
security	O
software	O
–	O
part	O
of	O
the	O
AV	O
definitions	O
was	O
out	O
of	O
testers	O
control	O
(	O
on	O
constantly	O
updated	O
AV	B-Application
company	I-Application
servers	O
)	O
thus	O
making	O
results	O
non-repeatable	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
Anti-Malware	B-Application
Testing	O
Standards	O
Organisation	O
(	O
AMTSO	O
)	O
started	O
working	O
on	O
method	O
of	O
testing	O
cloud	O
products	O
which	O
was	O
adopted	O
on	O
May	O
7	O
,	O
2009	O
.	O
</s>
<s>
In	O
2011	O
,	O
AVG	B-Application
introduced	O
a	O
similar	O
cloud	B-Architecture
service	I-Architecture
,	O
called	O
Protective	O
Cloud	B-Architecture
Technology	I-Architecture
.	O
</s>
<s>
Numerous	O
approaches	O
to	O
address	O
these	O
new	O
forms	O
of	O
threats	O
have	O
appeared	O
,	O
including	O
behavioral	O
detection	O
,	O
artificial	O
intelligence	O
,	O
machine	O
learning	O
,	O
and	O
cloud-based	B-Architecture
file	O
detonation	O
.	O
</s>
<s>
Increasingly	O
,	O
these	O
signature-less	O
approaches	O
have	O
been	O
defined	O
by	O
the	O
media	O
and	O
analyst	O
firms	O
as	O
"	O
next-generation	O
"	O
antivirus	B-Application
and	O
are	O
seeing	O
rapid	O
market	O
adoption	O
as	O
certified	O
antivirus	B-Application
replacement	O
technologies	O
by	O
firms	O
such	O
as	O
Coalfire	O
and	O
DirectDefense	O
.	O
</s>
<s>
In	O
response	O
,	O
traditional	O
antivirus	B-Application
vendors	O
such	O
as	O
Trend	O
Micro	O
,	O
Symantec	O
and	O
Sophos	O
have	O
responded	O
by	O
incorporating	O
"	O
next-gen	O
"	O
offerings	O
into	O
their	O
portfolios	O
as	O
analyst	O
firms	O
such	O
as	O
Forrester	O
and	O
Gartner	O
have	O
called	O
traditional	O
signature-based	O
antivirus	B-Application
"	O
ineffective	O
"	O
and	O
"	O
outdated	O
"	O
.	O
</s>
<s>
There	O
are	O
several	O
methods	O
which	O
antivirus	B-Application
engines	O
can	O
use	O
to	O
identify	O
malware	O
:	O
</s>
<s>
Sandbox	O
detection	O
:	O
a	O
particular	O
behavioural-based	O
detection	O
technique	O
that	O
,	O
instead	O
of	O
detecting	O
the	O
behavioural	O
fingerprint	O
at	O
run	O
time	O
,	O
it	O
executes	O
the	O
programs	O
in	O
a	O
virtual	B-Architecture
environment	I-Architecture
,	O
logging	O
what	O
actions	O
the	O
program	O
performs	O
.	O
</s>
<s>
Depending	O
on	O
the	O
actions	O
logged	O
,	O
the	O
antivirus	B-Application
engine	O
can	O
determine	O
if	O
the	O
program	O
is	O
malicious	O
or	O
not	O
.	O
</s>
<s>
Albeit	O
this	O
technique	O
has	O
shown	O
to	O
be	O
quite	O
effective	O
,	O
given	O
its	O
heaviness	O
and	O
slowness	O
,	O
it	O
is	O
rarely	O
used	O
in	O
end-user	O
antivirus	B-Application
solutions	O
.	O
</s>
<s>
Data	B-Application
mining	I-Application
techniques	O
:	O
one	O
of	O
the	O
latest	O
approaches	O
applied	O
in	O
malware	O
detection	O
.	O
</s>
<s>
Data	B-Application
mining	I-Application
and	O
machine	O
learning	O
algorithms	O
are	O
used	O
to	O
try	O
to	O
classify	O
the	O
behaviour	O
of	O
a	O
file	O
(	O
as	O
either	O
malicious	O
or	O
benign	O
)	O
given	O
a	O
series	O
of	O
file	O
features	O
,	O
that	O
are	O
extracted	O
from	O
the	O
file	O
itself	O
.	O
</s>
<s>
Traditional	O
antivirus	B-Application
software	I-Application
relies	O
heavily	O
upon	O
signatures	O
to	O
identify	O
malware	O
.	O
</s>
<s>
Substantially	O
,	O
when	O
a	O
malware	O
sample	O
arrives	O
in	O
the	O
hands	O
of	O
an	O
antivirus	B-Application
firm	O
,	O
it	O
is	O
analysed	O
by	O
malware	O
researchers	O
or	O
by	O
dynamic	O
analysis	O
systems	O
.	O
</s>
<s>
Then	O
,	O
once	O
it	O
is	O
determined	O
to	O
be	O
a	O
malware	O
,	O
a	O
proper	O
signature	O
of	O
the	O
file	O
is	O
extracted	O
and	O
added	O
to	O
the	O
signatures	O
database	O
of	O
the	O
antivirus	B-Application
software	I-Application
.	O
</s>
<s>
Although	O
the	O
signature-based	O
approach	O
can	O
effectively	O
contain	O
malware	O
outbreaks	O
,	O
malware	O
authors	O
have	O
tried	O
to	O
stay	O
a	O
step	O
ahead	O
of	O
such	O
software	O
by	O
writing	O
"	O
oligomorphic	B-Application
"	O
,	O
"	O
polymorphic	O
"	O
and	O
,	O
more	O
recently	O
,	O
"	O
metamorphic	O
"	O
viruses	O
,	O
which	O
encrypt	O
parts	O
of	O
themselves	O
or	O
otherwise	O
modify	O
themselves	O
as	O
a	O
method	O
of	O
disguise	O
,	O
so	O
as	O
to	O
not	O
match	O
virus	O
signatures	O
in	O
the	O
dictionary	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
Vundo	O
trojan	O
has	O
several	O
family	O
members	O
,	O
depending	O
on	O
the	O
antivirus	B-Application
vendor	O
's	O
classification	O
.	O
</s>
<s>
These	O
signatures	O
often	O
contain	O
non-contiguous	O
code	O
,	O
using	O
wildcard	B-Algorithm
characters	I-Algorithm
where	O
differences	O
lie	O
.	O
</s>
<s>
These	O
wildcards	B-Algorithm
allow	O
the	O
scanner	O
to	O
detect	O
viruses	O
even	O
if	O
they	O
are	O
padded	O
with	O
extra	O
,	O
meaningless	O
code	O
.	O
</s>
<s>
A	O
detection	O
that	O
uses	O
this	O
method	O
is	O
said	O
to	O
be	O
"	O
heuristic	B-Algorithm
detection.	O
"	O
</s>
<s>
Anti-virus	B-Application
software	I-Application
can	O
attempt	O
to	O
scan	O
for	O
rootkits	O
.	O
</s>
<s>
Rootkits	O
can	O
change	O
how	O
the	O
operating	B-General_Concept
system	I-General_Concept
functions	O
and	O
in	O
some	O
cases	O
can	O
tamper	O
with	O
the	O
anti-virus	B-Application
program	I-Application
and	O
render	O
it	O
ineffective	O
.	O
</s>
<s>
Rootkits	O
are	O
also	O
difficult	O
to	O
remove	O
,	O
in	O
some	O
cases	O
requiring	O
a	O
complete	O
re-installation	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Real-time	O
protection	O
,	O
on-access	O
scanning	O
,	O
background	O
guard	O
,	O
resident	O
shield	O
,	O
autoprotect	O
,	O
and	O
other	O
synonyms	O
refer	O
to	O
the	O
automatic	O
protection	O
provided	O
by	O
most	O
antivirus	B-Application
,	O
anti-spyware	O
,	O
and	O
other	O
anti-malware	B-Application
programs	O
.	O
</s>
<s>
Some	O
commercial	O
antivirus	B-Application
software	I-Application
end-user	O
license	O
agreements	O
include	O
a	O
clause	O
that	O
the	O
subscription	O
will	O
be	O
automatically	O
renewed	O
,	O
and	O
the	O
purchaser	O
's	O
credit	O
card	O
automatically	O
billed	O
,	O
at	O
the	O
renewal	O
time	O
without	O
explicit	O
approval	O
.	O
</s>
<s>
For	O
example	O
,	O
McAfee	O
requires	O
users	O
to	O
unsubscribe	O
at	O
least	O
60	O
days	O
before	O
the	O
expiration	O
of	O
the	O
present	O
subscription	O
while	O
BitDefender	B-Application
sends	O
notifications	O
to	O
unsubscribe	O
30	O
days	O
before	O
the	O
renewal	O
.	O
</s>
<s>
Norton	B-Application
AntiVirus	I-Application
also	O
renews	O
subscriptions	O
automatically	O
by	O
default	O
.	O
</s>
<s>
Some	O
apparent	O
antivirus	B-Application
programs	I-Application
are	O
actually	O
malware	O
masquerading	O
as	O
legitimate	O
software	O
,	O
such	O
as	O
WinFixer	O
,	O
MS	O
Antivirus	B-Application
,	O
and	O
Mac	O
Defender	O
.	O
</s>
<s>
A	O
"	O
false	O
positive	O
"	O
or	O
"	O
false	O
alarm	O
"	O
is	O
when	O
antivirus	B-Application
software	I-Application
identifies	O
a	O
non-malicious	O
file	O
as	O
malware	O
.	O
</s>
<s>
For	O
example	O
,	O
if	O
an	O
antivirus	B-Application
program	I-Application
is	O
configured	O
to	O
immediately	O
delete	O
or	O
quarantine	B-Application
infected	O
files	O
,	O
as	O
is	O
common	O
on	O
Microsoft	B-Application
Windows	I-Application
antivirus	B-Application
applications	O
,	O
a	O
false	O
positive	O
in	O
an	O
essential	O
file	O
can	O
render	O
the	O
Windows	B-Application
operating	I-Application
system	I-Application
or	O
some	O
applications	O
unusable	O
.	O
</s>
<s>
May	O
2007	O
:	O
a	O
faulty	O
virus	O
signature	O
issued	O
by	O
Symantec	O
mistakenly	O
removed	O
essential	O
operating	B-General_Concept
system	I-General_Concept
files	O
,	O
leaving	O
thousands	O
of	O
PCs	O
unable	O
to	O
boot	B-Operating_System
.	O
</s>
<s>
May	O
2007	O
:	O
the	O
executable	B-Application
file	I-Application
required	O
by	O
Pegasus	B-Application
Mail	I-Application
on	O
Windows	O
was	O
falsely	O
detected	O
by	O
Norton	B-Application
AntiVirus	I-Application
as	O
being	O
a	O
Trojan	O
and	O
it	O
was	O
automatically	O
removed	O
,	O
preventing	O
Pegasus	B-Application
Mail	I-Application
from	O
running	O
.	O
</s>
<s>
Norton	B-Application
AntiVirus	I-Application
had	O
falsely	O
identified	O
three	O
releases	O
of	O
Pegasus	B-Application
Mail	I-Application
as	O
malware	O
,	O
and	O
would	O
delete	O
the	O
Pegasus	B-Application
Mail	I-Application
installer	O
file	O
when	O
that	O
happened	O
.	O
</s>
<s>
In	O
response	O
to	O
this	O
Pegasus	B-Application
Mail	I-Application
stated	O
:	O
</s>
<s>
April	O
2010	O
:	O
McAfee	B-Operating_System
VirusScan	I-Operating_System
detected	O
svchost.exe	O
,	O
a	O
normal	O
Windows	O
binary	O
,	O
as	O
a	O
virus	O
on	O
machines	O
running	O
Windows	B-Application
XP	I-Application
with	O
Service	O
Pack	O
3	O
,	O
causing	O
a	O
reboot	O
loop	O
and	O
loss	O
of	O
all	O
network	B-General_Concept
access	O
.	O
</s>
<s>
December	O
2010	O
:	O
a	O
faulty	O
update	O
on	O
the	O
AVG	B-Application
anti-virus	I-Application
suite	O
damaged	O
64-bit	O
versions	O
of	O
Windows	B-Device
7	I-Device
,	O
rendering	O
it	O
unable	O
to	O
boot	B-Operating_System
,	O
due	O
to	O
an	O
endless	O
boot	B-Operating_System
loop	O
created	O
.	O
</s>
<s>
October	O
2011	O
:	O
Microsoft	B-Application
Security	I-Application
Essentials	I-Application
(	O
MSE	O
)	O
removed	O
the	O
Google	B-Application
Chrome	I-Application
web	O
browser	O
,	O
rival	O
to	O
Microsoft	O
's	O
own	O
Internet	B-Application
Explorer	I-Application
.	O
</s>
<s>
MSE	O
flagged	O
Chrome	B-Application
as	O
a	O
Zbot	O
banking	O
trojan	O
.	O
</s>
<s>
September	O
2012	O
:	O
Sophos	O
 '	O
anti-virus	B-Application
suite	O
identified	O
various	O
update-mechanisms	O
,	O
including	O
its	O
own	O
,	O
as	O
malware	O
.	O
</s>
<s>
If	O
it	O
was	O
configured	O
to	O
automatically	O
delete	O
detected	O
files	O
,	O
Sophos	O
Antivirus	B-Application
could	O
render	O
itself	O
unable	O
to	O
update	O
,	O
required	O
manual	O
intervention	O
to	O
fix	O
the	O
problem	O
.	O
</s>
<s>
September	O
2017	O
:	O
the	O
Google	O
Play	O
Protect	O
anti-virus	B-Application
started	O
identifying	O
Motorola	O
's	O
Moto	B-Application
G4	I-Application
Bluetooth	O
application	O
as	O
malware	O
,	O
causing	O
Bluetooth	O
functionality	O
to	O
become	O
disabled	O
.	O
</s>
<s>
September	O
2022	O
:	O
Microsoft	B-Application
Defender	I-Application
flagged	O
all	O
Chromium	O
based	O
web	O
browsers	O
and	O
Electron	O
based	O
apps	O
like	O
Whatsapp	O
,	O
Discord	O
,	O
Spotify	O
as	O
a	O
severe	O
threat	O
.	O
</s>
<s>
Running	O
(	O
the	O
real-time	O
protection	O
of	O
)	O
multiple	O
antivirus	B-Application
programs	I-Application
concurrently	O
can	O
degrade	O
performance	O
and	O
create	O
conflicts	O
.	O
</s>
<s>
However	O
,	O
using	O
a	O
concept	O
called	O
multiscanning	O
,	O
several	O
companies	O
(	O
including	O
G	B-Application
Data	I-Application
Software	I-Application
and	O
Microsoft	O
)	O
have	O
created	O
applications	O
which	O
can	O
run	O
multiple	O
engines	O
concurrently	O
.	O
</s>
<s>
It	O
is	O
sometimes	O
necessary	O
to	O
temporarily	O
disable	O
virus	B-Application
protection	I-Application
when	O
installing	O
major	O
updates	O
such	O
as	O
Windows	O
Service	O
Packs	O
or	O
updating	O
graphics	O
card	O
drivers	O
.	O
</s>
<s>
Active	O
antivirus	B-Application
protection	O
may	O
partially	O
or	O
completely	O
prevent	O
the	O
installation	O
of	O
a	O
major	O
update	O
.	O
</s>
<s>
Anti-virus	B-Application
software	I-Application
can	O
cause	O
problems	O
during	O
the	O
installation	O
of	O
an	O
operating	B-General_Concept
system	I-General_Concept
upgrade	O
,	O
e.g.	O
</s>
<s>
Microsoft	O
recommends	O
that	O
anti-virus	B-Application
software	I-Application
be	O
disabled	O
to	O
avoid	O
conflicts	O
with	O
the	O
upgrade	O
installation	O
process	O
.	O
</s>
<s>
Active	O
anti-virus	B-Application
software	I-Application
can	O
also	O
interfere	O
with	O
a	O
firmware	B-Application
update	O
process	O
.	O
</s>
<s>
The	O
functionality	O
of	O
a	O
few	O
computer	B-Application
programs	I-Application
can	O
be	O
hampered	O
by	O
active	O
anti-virus	B-Application
software	I-Application
.	O
</s>
<s>
For	O
example	O
,	O
TrueCrypt	B-Application
,	O
a	O
disk	O
encryption	O
program	O
,	O
states	O
on	O
its	O
troubleshooting	O
page	O
that	O
anti-virus	B-Application
programs	I-Application
can	O
conflict	O
with	O
TrueCrypt	B-Application
and	O
cause	O
it	O
to	O
malfunction	O
or	O
operate	O
very	O
slowly	O
.	O
</s>
<s>
Anti-virus	B-Application
software	I-Application
can	O
impair	O
the	O
performance	O
and	O
stability	O
of	O
games	O
running	O
in	O
the	O
Steam	B-Application
platform	O
.	O
</s>
<s>
Support	O
issues	O
also	O
exist	O
around	O
antivirus	B-Application
application	O
interoperability	O
with	O
common	O
solutions	O
like	O
SSL	B-Application
VPN	I-Application
remote	I-Application
access	I-Application
and	O
network	B-General_Concept
access	O
control	O
products	O
.	O
</s>
<s>
These	O
technology	O
solutions	O
often	O
have	O
policy	O
assessment	O
applications	O
that	O
require	O
an	O
up-to-date	O
antivirus	B-Application
to	O
be	O
installed	O
and	O
running	O
.	O
</s>
<s>
If	O
the	O
antivirus	B-Application
application	O
is	O
not	O
recognized	O
by	O
the	O
policy	O
assessment	O
,	O
whether	O
because	O
the	O
antivirus	B-Application
application	O
has	O
been	O
updated	O
or	O
because	O
it	O
is	O
not	O
part	O
of	O
the	O
policy	O
assessment	O
library	O
,	O
the	O
user	O
will	O
be	O
unable	O
to	O
connect	O
.	O
</s>
<s>
Studies	O
in	O
December	O
2007	O
showed	O
that	O
the	O
effectiveness	O
of	O
antivirus	B-Application
software	I-Application
had	O
decreased	O
in	O
the	O
previous	O
year	O
,	O
particularly	O
against	O
unknown	O
or	O
zero	O
day	O
attacks	O
.	O
</s>
<s>
At	O
that	O
time	O
,	O
the	O
only	O
exception	O
was	O
the	O
NOD32	B-Application
antivirus	I-Application
,	O
which	O
managed	O
a	O
detection	O
rate	O
of	O
68%	O
.	O
</s>
<s>
In	O
2008	O
,	O
Eva	O
Chen	O
,	O
CEO	B-Application
of	O
Trend	O
Micro	O
,	O
stated	O
that	O
the	O
anti-virus	B-Application
industry	O
has	O
over-hyped	O
how	O
effective	O
its	O
products	O
are	O
—	O
and	O
so	O
has	O
been	O
misleading	O
customers	O
—	O
for	O
years	O
.	O
</s>
<s>
Independent	O
testing	O
on	O
all	O
the	O
major	O
virus	B-Application
scanners	I-Application
consistently	O
shows	O
that	O
none	O
provides	O
100%	O
virus	O
detection	O
.	O
</s>
<s>
Many	O
virus	B-Application
scanners	I-Application
produce	O
false	O
positive	O
results	O
as	O
well	O
,	O
identifying	O
benign	O
files	O
as	O
malware	O
.	O
</s>
<s>
Although	O
methods	O
may	O
differ	O
,	O
some	O
notable	O
independent	O
quality	O
testing	O
agencies	O
include	O
AV-Comparatives	O
,	O
ICSA	O
Labs	O
,	O
West	O
Coast	O
Labs	O
,	O
Virus	O
Bulletin	O
,	O
AV-TEST	O
and	O
other	O
members	O
of	O
the	O
Anti-Malware	B-Application
Testing	O
Standards	O
Organization	O
.	O
</s>
<s>
Anti-virus	B-Application
programs	I-Application
are	O
not	O
always	O
effective	O
against	O
new	O
viruses	O
,	O
even	O
those	O
that	O
use	O
non-signature-based	O
methods	O
that	O
should	O
detect	O
new	O
viruses	O
.	O
</s>
<s>
The	O
reason	O
for	O
this	O
is	O
that	O
the	O
virus	O
designers	O
test	O
their	O
new	O
viruses	O
on	O
the	O
major	O
anti-virus	B-Application
applications	O
to	O
make	O
sure	O
that	O
they	O
are	O
not	O
detected	O
before	O
releasing	O
them	O
into	O
the	O
wild	O
.	O
</s>
<s>
Some	O
new	O
viruses	O
,	O
particularly	O
ransomware	O
,	O
use	O
polymorphic	O
code	O
to	O
avoid	O
detection	O
by	O
virus	B-Application
scanners	I-Application
.	O
</s>
<s>
A	O
proof	O
of	O
concept	O
virus	O
has	O
used	O
the	O
Graphics	B-Architecture
Processing	I-Architecture
Unit	I-Architecture
(	O
GPU	B-Architecture
)	O
to	O
avoid	O
detection	O
from	O
anti-virus	B-Application
software	I-Application
.	O
</s>
<s>
The	O
potential	O
success	O
of	O
this	O
involves	O
bypassing	O
the	O
CPU	B-General_Concept
in	O
order	O
to	O
make	O
it	O
much	O
harder	O
for	O
security	O
researchers	O
to	O
analyse	O
the	O
inner	O
workings	O
of	O
such	O
malware	O
.	O
</s>
<s>
Detecting	O
rootkits	O
is	O
a	O
major	O
challenge	O
for	O
anti-virus	B-Application
programs	I-Application
.	O
</s>
<s>
Rootkits	O
have	O
full	O
administrative	O
access	O
to	O
the	O
computer	O
and	O
are	O
invisible	O
to	O
users	O
and	O
hidden	O
from	O
the	O
list	O
of	O
running	O
processes	O
in	O
the	O
task	B-General_Concept
manager	I-General_Concept
.	O
</s>
<s>
Rootkits	O
can	O
modify	O
the	O
inner	O
workings	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
tamper	O
with	O
antivirus	B-Application
programs	I-Application
.	O
</s>
<s>
If	O
a	O
file	O
has	O
been	O
infected	O
by	O
a	O
computer	O
virus	O
,	O
anti-virus	B-Application
software	I-Application
will	O
attempt	O
to	O
remove	O
the	O
virus	O
code	O
from	O
the	O
file	O
during	O
disinfection	O
,	O
but	O
it	O
is	O
not	O
always	O
able	O
to	O
restore	O
the	O
file	O
to	O
its	O
undamaged	O
state	O
.	O
</s>
<s>
Any	O
writeable	O
firmware	B-Application
in	O
the	O
computer	O
can	O
be	O
infected	O
by	O
malicious	O
code	O
.	O
</s>
<s>
This	O
is	O
a	O
major	O
concern	O
,	O
as	O
an	O
infected	O
BIOS	B-Operating_System
could	O
require	O
the	O
actual	O
BIOS	B-Operating_System
chip	I-Operating_System
to	O
be	O
replaced	O
to	O
ensure	O
the	O
malicious	O
code	O
is	O
completely	O
removed	O
.	O
</s>
<s>
Anti-virus	B-Application
software	I-Application
is	O
not	O
effective	O
at	O
protecting	O
firmware	B-Application
and	O
the	O
motherboard	B-Device
BIOS	B-Operating_System
from	O
infection	O
.	O
</s>
<s>
In	O
2014	O
,	O
security	O
researchers	O
discovered	O
that	O
USB	B-Protocol
devices	O
contain	O
writeable	O
firmware	B-Application
which	O
can	O
be	O
modified	O
with	O
malicious	O
code	O
(	O
dubbed	O
"	O
BadUSB	O
"	O
)	O
,	O
which	O
anti-virus	B-Application
software	I-Application
cannot	O
detect	O
or	O
prevent	O
.	O
</s>
<s>
The	O
malicious	O
code	O
can	O
run	O
undetected	O
on	O
the	O
computer	O
and	O
could	O
even	O
infect	O
the	O
operating	B-General_Concept
system	I-General_Concept
prior	O
to	O
it	O
booting	B-Operating_System
up	I-Operating_System
.	O
</s>
<s>
Antivirus	B-Application
software	I-Application
has	O
some	O
drawbacks	O
,	O
first	O
of	O
which	O
that	O
it	O
can	O
impact	O
a	O
computer	O
's	O
performance	O
.	O
</s>
<s>
Furthermore	O
,	O
inexperienced	O
users	O
can	O
be	O
lulled	O
into	O
a	O
false	O
sense	O
of	O
security	O
when	O
using	O
the	O
computer	O
,	O
considering	O
their	O
computers	O
to	O
be	O
invulnerable	O
,	O
and	O
may	O
have	O
problems	O
understanding	O
the	O
prompts	O
and	O
decisions	O
that	O
antivirus	B-Application
software	I-Application
presents	O
them	O
with	O
.	O
</s>
<s>
If	O
the	O
antivirus	B-Application
software	I-Application
employs	O
heuristic	B-Algorithm
detection	O
,	O
it	O
must	O
be	O
fine-tuned	O
to	O
minimize	O
misidentifying	O
harmless	O
software	O
as	O
malicious	O
(	O
false	O
positive	O
)	O
.	O
</s>
<s>
Antivirus	B-Application
software	I-Application
itself	O
usually	O
runs	O
at	O
the	O
highly	O
trusted	O
kernel	B-Operating_System
level	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
to	O
allow	O
it	O
access	O
to	O
all	O
the	O
potential	O
malicious	O
process	O
and	O
files	O
,	O
creating	O
a	O
potential	O
avenue	O
of	O
attack	O
.	O
</s>
<s>
respectively	O
,	O
have	O
been	O
exploiting	O
anti-virus	B-Application
software	I-Application
to	O
spy	O
on	O
users	O
.	O
</s>
<s>
Anti-virus	B-Application
software	I-Application
has	O
highly	O
privileged	O
and	O
trusted	O
access	O
to	O
the	O
underlying	O
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
makes	O
it	O
a	O
much	O
more	O
appealing	O
target	O
for	O
remote	O
attacks	O
.	O
</s>
<s>
Additionally	O
anti-virus	B-Application
software	I-Application
is	O
"	O
years	O
behind	O
security-conscious	O
client-side	O
applications	O
like	O
browsers	O
or	O
document	O
readers	O
.	O
</s>
<s>
It	O
means	O
that	O
Acrobat	O
Reader	O
,	O
Microsoft	B-Application
Word	I-Application
or	O
Google	B-Application
Chrome	I-Application
are	O
harder	O
to	O
exploit	O
than	O
90	O
percent	O
of	O
the	O
anti-virus	B-Application
products	I-Application
out	O
there	O
"	O
,	O
according	O
to	O
Joxean	O
Koret	O
,	O
a	O
researcher	O
with	O
Coseinc	O
,	O
a	O
Singapore-based	O
information	O
security	O
consultancy	O
.	O
</s>
<s>
Antivirus	B-Application
software	I-Application
running	O
on	O
individual	O
computers	O
is	O
the	O
most	O
common	O
method	O
employed	O
of	O
guarding	O
against	O
malware	O
,	O
but	O
it	O
is	O
not	O
the	O
only	O
solution	O
.	O
</s>
<s>
Other	O
solutions	O
can	O
also	O
be	O
employed	O
by	O
users	O
,	O
including	O
Unified	O
Threat	O
Management	O
(	O
UTM	O
)	O
,	O
hardware	O
and	O
network	B-Application
firewalls	I-Application
,	O
Cloud-based	B-Architecture
antivirus	B-Application
and	O
online	O
scanners	O
.	O
</s>
<s>
Network	B-Application
firewalls	I-Application
prevent	O
unknown	O
programs	O
and	O
processes	O
from	O
accessing	O
the	O
system	O
.	O
</s>
<s>
However	O
,	O
they	O
are	O
not	O
antivirus	B-Application
systems	O
and	O
make	O
no	O
attempt	O
to	O
identify	O
or	O
remove	O
anything	O
.	O
</s>
<s>
They	O
may	O
protect	O
against	O
infection	O
from	O
outside	O
the	O
protected	O
computer	O
or	O
network	B-General_Concept
,	O
and	O
limit	O
the	O
activity	O
of	O
any	O
malicious	O
software	O
which	O
is	O
present	O
by	O
blocking	O
incoming	O
or	O
outgoing	O
requests	O
on	O
certain	O
TCP/IP	B-Protocol
ports	I-Protocol
.	O
</s>
<s>
A	O
firewall	B-Application
is	O
designed	O
to	O
deal	O
with	O
broader	O
system	O
threats	O
that	O
come	O
from	O
network	B-General_Concept
connections	O
into	O
the	O
system	O
and	O
is	O
not	O
an	O
alternative	O
to	O
a	O
virus	B-Application
protection	I-Application
system	O
.	O
</s>
<s>
Cloud	O
antivirus	B-Application
is	O
a	O
technology	O
that	O
uses	O
lightweight	O
agent	O
software	O
on	O
the	O
protected	O
computer	O
,	O
while	O
offloading	O
the	O
majority	O
of	O
data	O
analysis	O
to	O
the	O
provider	O
's	O
infrastructure	O
.	O
</s>
<s>
One	O
approach	O
to	O
implementing	O
cloud	O
antivirus	B-Application
involves	O
scanning	O
suspicious	O
files	O
using	O
multiple	O
antivirus	B-Application
engines	O
.	O
</s>
<s>
This	O
approach	O
was	O
proposed	O
by	O
an	O
early	O
implementation	O
of	O
the	O
cloud	O
antivirus	B-Application
concept	O
called	O
CloudAV	O
.	O
</s>
<s>
CloudAV	O
was	O
designed	O
to	O
send	O
programs	O
or	O
documents	O
to	O
a	O
network	B-Architecture
cloud	I-Architecture
where	O
multiple	O
antivirus	B-Application
and	O
behavioral	O
detection	O
programs	O
are	O
used	O
simultaneously	O
in	O
order	O
to	O
improve	O
detection	O
rates	O
.	O
</s>
<s>
Parallel	O
scanning	O
of	O
files	O
using	O
potentially	O
incompatible	O
antivirus	B-Application
scanners	I-Application
is	O
achieved	O
by	O
spawning	O
a	O
virtual	B-Architecture
machine	I-Architecture
per	O
detection	O
engine	O
and	O
therefore	O
eliminating	O
any	O
possible	O
issues	O
.	O
</s>
<s>
Some	O
examples	O
of	O
cloud	O
anti-virus	B-Application
products	I-Application
are	O
Panda	B-Application
Cloud	I-Application
Antivirus	I-Application
and	O
Immunet	B-Application
.	O
</s>
<s>
Comodo	O
Group	O
has	O
also	O
produced	O
cloud-based	B-Architecture
anti-virus	B-Application
.	O
</s>
<s>
Some	O
antivirus	B-Application
vendors	O
maintain	O
websites	O
with	O
free	O
online	O
scanning	O
capability	O
of	O
the	O
entire	O
computer	O
,	O
critical	O
areas	O
only	O
,	O
local	O
disks	O
,	O
folders	O
or	O
files	O
.	O
</s>
<s>
Periodic	O
online	O
scanning	O
is	O
a	O
good	O
idea	O
for	O
those	O
that	O
run	O
antivirus	B-Application
applications	O
on	O
their	O
computers	O
because	O
those	O
applications	O
are	O
frequently	O
slow	O
to	O
catch	O
threats	O
.	O
</s>
<s>
One	O
of	O
the	O
first	O
things	O
that	O
malicious	O
software	O
does	O
in	O
an	O
attack	O
is	O
disable	O
any	O
existing	O
antivirus	B-Application
software	I-Application
and	O
sometimes	O
the	O
only	O
way	O
to	O
know	O
of	O
an	O
attack	O
is	O
by	O
turning	O
to	O
an	O
online	O
resource	O
that	O
is	O
not	O
installed	O
on	O
the	O
infected	O
computer	O
.	O
</s>
<s>
Virus	B-Application
removal	I-Application
tools	I-Application
are	O
available	O
to	O
help	O
remove	O
stubborn	O
infections	O
or	O
a	O
certain	O
type	O
of	O
infection	O
.	O
</s>
<s>
Examples	O
include	O
Windows	B-Application
Malicious	I-Application
Software	I-Application
Removal	I-Application
Tool	I-Application
,	O
Sophos	O
Scan	O
&	O
Clean	O
,	O
and	O
Kaspersky	O
Virus	B-Application
Removal	I-Application
Tool	I-Application
.	O
</s>
<s>
It	O
is	O
also	O
worth	O
noting	O
that	O
sometimes	O
antivirus	B-Application
software	I-Application
can	O
produce	O
a	O
false-positive	O
result	O
,	O
indicating	O
an	O
infection	O
where	O
there	O
is	O
none	O
.	O
</s>
<s>
A	O
rescue	O
disk	O
that	O
is	O
bootable	B-Operating_System
,	O
such	O
as	O
a	O
CD	O
or	O
USB	B-Protocol
storage	O
device	O
,	O
can	O
be	O
used	O
to	O
run	O
antivirus	B-Application
software	I-Application
outside	O
of	O
the	O
installed	O
operating	B-General_Concept
system	I-General_Concept
in	O
order	O
to	O
remove	O
infections	O
while	O
they	O
are	O
dormant	O
.	O
</s>
<s>
A	O
bootable	B-Operating_System
antivirus	B-Application
disk	O
can	O
be	O
useful	O
when	O
,	O
for	O
example	O
,	O
the	O
installed	O
operating	B-General_Concept
system	I-General_Concept
is	O
no	O
longer	O
bootable	B-Operating_System
or	O
has	O
malware	O
that	O
is	O
resisting	O
all	O
attempts	O
to	O
be	O
removed	O
by	O
the	O
installed	O
antivirus	B-Application
software	I-Application
.	O
</s>
<s>
Examples	O
of	O
some	O
of	O
these	O
bootable	B-Operating_System
disks	O
include	O
the	O
Trend	O
Micro	O
Rescue	O
Disk	O
,	O
Kaspersky	O
Rescue	O
Disk	O
,	O
and	O
Comodo	O
Rescue	O
Disk	O
.	O
</s>
<s>
Most	O
of	O
the	O
rescue	O
disk	O
software	O
can	O
also	O
be	O
installed	O
onto	O
a	O
USB	B-Protocol
storage	O
device	O
that	O
is	O
bootable	B-Operating_System
on	O
newer	O
computers	O
.	O
</s>
<s>
A	O
survey	O
by	O
Symantec	O
in	O
2009	O
found	O
that	O
a	O
third	O
of	O
small	O
to	O
medium-sized	O
business	O
did	O
not	O
use	O
antivirus	B-Application
protection	O
at	O
that	O
time	O
,	O
whereas	O
more	O
than	O
80%	O
of	O
home	O
users	O
had	O
some	O
kind	O
of	O
antivirus	B-Application
installed	O
.	O
</s>
<s>
According	O
to	O
a	O
sociological	O
survey	O
conducted	O
by	O
G	B-Application
Data	I-Application
Software	I-Application
in	O
2010	O
49%	O
of	O
women	O
did	O
not	O
use	O
any	O
antivirus	B-Application
program	I-Application
at	O
all	O
.	O
</s>
