<s>
Linux	B-Application
malware	I-Application
includes	O
viruses	O
,	O
Trojans	O
,	O
worms	O
and	O
other	O
types	O
of	O
malware	O
that	O
affect	O
the	O
Linux	B-Application
family	O
of	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Linux	B-Application
,	O
Unix	B-Application
and	O
other	O
Unix-like	B-Operating_System
computer	B-General_Concept
operating	I-General_Concept
systems	I-General_Concept
are	O
generally	O
regarded	O
as	O
very	O
well-protected	O
against	O
,	O
but	O
not	O
immune	O
to	O
,	O
computer	O
viruses	O
.	O
</s>
<s>
Like	O
Unix	B-Application
systems	I-Application
,	O
Linux	B-Application
implements	O
a	O
multi-user	B-Operating_System
environment	O
where	O
users	O
are	O
granted	O
specific	O
privileges	O
and	O
there	O
is	O
some	O
form	O
of	O
access	O
control	O
implemented	O
.	O
</s>
<s>
To	O
gain	O
control	O
over	O
a	O
Linux	B-Application
system	O
or	O
to	O
cause	O
any	O
serious	O
consequences	O
to	O
the	O
system	O
itself	O
,	O
the	O
malware	O
would	O
have	O
to	O
gain	O
root	O
access	O
to	O
the	O
system	O
.	O
</s>
<s>
In	O
the	O
past	O
,	O
it	O
has	O
been	O
suggested	O
that	O
Linux	B-Application
had	O
so	O
little	O
malware	O
because	O
its	O
low	O
market	O
share	O
made	O
it	O
a	O
less	O
profitable	O
target	O
.	O
</s>
<s>
Rick	O
Moen	O
,	O
an	O
experienced	O
Linux	B-Application
system	O
administrator	O
,	O
counters	O
that	O
:	O
</s>
<s>
In	O
2008	O
the	O
quantity	O
of	O
malware	O
targeting	O
Linux	B-Application
was	O
noted	O
as	O
increasing	O
.	O
</s>
<s>
Shane	O
Coursen	O
,	O
a	O
senior	O
technical	O
consultant	O
with	O
Kaspersky	B-Application
Lab	O
,	O
said	O
at	O
the	O
time	O
,	O
"	O
The	O
growth	O
in	O
Linux	B-Application
malware	I-Application
is	O
simply	O
due	O
to	O
its	O
increasing	O
popularity	O
,	O
particularly	O
as	O
a	O
desktop	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
...	O
</s>
<s>
The	O
use	O
of	O
an	O
operating	B-General_Concept
system	I-General_Concept
is	O
directly	O
correlated	O
to	O
the	O
interest	O
by	O
the	O
malware	O
writers	O
to	O
develop	O
malware	O
for	O
that	O
OS.	O
"	O
</s>
<s>
Tom	O
Ferris	O
,	O
a	O
researcher	O
with	O
Security	O
Protocols	O
,	O
commented	O
on	O
one	O
of	O
Kaspersky	B-Application
's	O
reports	O
,	O
stating	O
,	O
"	O
In	O
people	O
's	O
minds	O
,	O
if	O
it	O
's	O
non-Windows	O
,	O
it	O
's	O
secure	O
,	O
and	O
that	O
's	O
not	O
the	O
case	O
.	O
</s>
<s>
They	O
think	O
nobody	O
writes	O
malware	O
for	O
Linux	B-Application
or	O
Mac	O
OS	O
X	O
.	O
</s>
<s>
Some	O
Linux	B-Application
users	O
do	O
run	O
Linux-based	O
anti-virus	O
software	O
to	O
scan	O
insecure	O
documents	O
and	O
email	O
which	O
comes	O
from	O
or	O
is	O
going	O
to	O
Windows	O
users	O
.	O
</s>
<s>
Because	O
they	O
are	O
predominantly	O
used	O
on	O
mail	O
servers	O
which	O
may	O
send	O
mail	O
to	O
computers	O
running	O
other	O
operating	B-General_Concept
systems	I-General_Concept
,	O
Linux	B-Application
virus	I-Application
scanners	O
generally	O
use	O
definitions	O
for	O
,	O
and	O
scan	O
for	O
,	O
all	O
known	O
viruses	O
for	O
all	O
computer	O
platforms	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
open	O
source	O
ClamAV	B-Application
"	O
Detects	O
...	O
viruses	O
,	O
worms	O
and	O
trojans	O
,	O
including	O
Microsoft	O
Office	O
macro	O
viruses	O
,	O
mobile	B-Application
malware	I-Application
,	O
and	O
other	O
threats.	O
"	O
</s>
<s>
The	O
viruses	O
listed	O
below	O
pose	O
a	O
potential	O
,	O
although	O
minimal	O
,	O
threat	O
to	O
Linux	B-Application
systems	O
.	O
</s>
<s>
If	O
an	O
infected	O
binary	O
containing	O
one	O
of	O
the	O
viruses	O
were	O
run	O
,	O
the	O
system	O
would	O
be	O
temporarily	O
infected	O
,	O
as	O
the	O
Linux	B-Application
kernel	O
is	O
memory	O
resident	O
and	O
read-only	O
.	O
</s>
<s>
The	O
use	O
of	O
software	B-Application
repositories	I-Application
significantly	O
reduces	O
any	O
threat	O
of	O
installation	O
of	O
malware	O
,	O
as	O
the	O
software	B-Application
repositories	I-Application
are	O
checked	O
by	O
maintainers	O
,	O
who	O
try	O
to	O
ensure	O
that	O
their	O
repository	O
is	O
malware-free	O
.	O
</s>
<s>
Subsequently	O
,	O
to	O
ensure	O
safe	O
distribution	O
of	O
the	O
software	O
,	O
checksums	B-Algorithm
are	O
made	O
available	O
.	O
</s>
<s>
Careful	O
use	O
of	O
these	O
digital	O
signatures	O
provides	O
an	O
additional	O
line	O
of	O
defense	O
,	O
which	O
limits	O
the	O
scope	O
of	O
attacks	O
to	O
include	O
only	O
the	O
original	O
authors	O
,	O
package	O
and	O
release	O
maintainers	O
and	O
possibly	O
others	O
with	O
suitable	O
administrative	O
access	O
,	O
depending	O
on	O
how	O
the	O
keys	O
and	O
checksums	B-Algorithm
are	O
handled	O
.	O
</s>
<s>
Reproducible	B-Application
builds	I-Application
can	O
ensure	O
that	O
digitally	O
signed	O
source	O
code	O
has	O
been	O
reliably	O
transformed	O
into	O
a	O
binary	O
application	O
.	O
</s>
<s>
The	O
classical	O
threat	O
to	O
Unix-like	B-Operating_System
systems	I-Operating_System
are	O
vulnerabilities	O
in	O
network	O
daemons	B-Operating_System
,	O
such	O
as	O
SSH	O
and	O
web	O
servers	O
.	O
</s>
<s>
Linux	B-Application
servers	O
may	O
also	O
be	O
used	O
by	O
malware	O
without	O
any	O
attack	O
against	O
the	O
system	O
itself	O
,	O
where	O
e.g.	O
</s>
<s>
Some	O
attacks	O
use	O
complicated	O
malware	O
to	O
attack	O
Linux	B-Application
servers	O
,	O
but	O
when	O
most	O
get	O
full	O
root	O
access	O
then	O
hackers	O
are	O
able	O
to	O
attack	O
by	O
modifying	O
anything	O
like	O
replacing	O
binaries	O
or	O
injecting	O
modules	O
.	O
</s>
<s>
Typically	O
,	O
a	O
CGI	B-Language
script	I-Language
meant	O
for	O
leaving	O
comments	O
,	O
could	O
,	O
by	O
mistake	O
,	O
allow	O
inclusion	O
of	O
code	O
exploiting	O
vulnerabilities	O
in	O
the	O
web	O
browser	O
.	O
</s>
<s>
Older	O
Linux	B-Application
distributions	O
were	O
relatively	O
sensitive	O
to	O
buffer	B-General_Concept
overflow	I-General_Concept
attacks	O
:	O
if	O
the	O
program	O
did	O
not	O
care	O
about	O
the	O
size	O
of	O
the	O
buffer	O
itself	O
,	O
the	O
kernel	O
provided	O
only	O
limited	O
protection	O
,	O
allowing	O
an	O
attacker	O
to	O
execute	O
arbitrary	O
code	O
under	O
the	O
rights	O
of	O
the	O
vulnerable	O
application	O
under	O
attack	O
.	O
</s>
<s>
An	O
area	O
of	O
concern	O
identified	O
in	O
2007	O
is	O
that	O
of	O
cross-platform	B-Operating_System
viruses	O
,	O
driven	O
by	O
the	O
popularity	O
of	O
cross-platform	B-Operating_System
applications	O
.	O
</s>
<s>
This	O
was	O
brought	O
to	O
the	O
forefront	O
of	O
malware	O
awareness	O
by	O
the	O
distribution	O
of	O
an	O
OpenOffice.org	B-Application
virus	O
called	O
Badbunny	B-Application
.	O
</s>
<s>
The	O
ability	O
for	O
malware	O
to	O
survive	O
in	O
a	O
cross-platform	B-Operating_System
,	O
cross-application	O
environment	O
has	O
particular	O
relevance	O
as	O
more	O
and	O
more	O
malware	O
is	O
pushed	O
out	O
via	O
Web	O
sites	O
.	O
</s>
<s>
As	O
is	O
the	O
case	O
with	O
any	O
operating	B-General_Concept
system	I-General_Concept
,	O
Linux	B-Application
is	O
vulnerable	O
to	O
malware	O
that	O
tricks	O
the	O
user	O
into	O
installing	O
it	O
through	O
social	O
engineering	O
.	O
</s>
<s>
In	O
December	O
2009	O
a	O
malicious	O
waterfall	O
screensaver	O
that	O
contained	O
a	O
script	O
that	O
used	O
the	O
infected	O
Linux	B-Application
PC	O
in	O
denial-of-service	O
attacks	O
was	O
discovered	O
.	O
</s>
<s>
That	O
these	O
cybercriminals	O
are	O
increasingly	O
using	O
Linux	B-Application
and	O
Unix	B-Application
to	O
target	O
hospitals	O
and	O
allied	O
industries	O
(	O
that	O
rely	O
on	O
these	O
systems	O
and	O
cloud	O
networks	O
)	O
that	O
they	O
are	O
increasingly	O
vulnerable	O
during	O
the	O
Covid-19	O
crisis	O
,	O
such	O
as	O
the	O
Red	O
Cross	O
cyberattack	O
.	O
</s>
<s>
There	O
are	O
a	O
number	O
of	O
anti-virus	O
applications	O
available	O
which	O
will	O
run	O
under	O
the	O
Linux	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
Most	O
of	O
these	O
applications	O
are	O
looking	O
for	O
exploits	O
which	O
could	O
affect	O
users	O
of	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
These	O
applications	O
are	O
useful	O
for	O
computers	O
(	O
typically	O
,	O
servers	O
)	O
which	O
will	O
pass	O
on	O
files	O
to	O
Microsoft	B-Application
Windows	I-Application
users	O
.	O
</s>
<s>
They	O
do	O
not	O
look	O
for	O
Linux-specific	O
threats	O
.	O
</s>
<s>
These	O
applications	O
look	O
for	O
actual	O
threats	O
to	O
the	O
Linux	B-Application
computers	O
on	O
which	O
they	O
are	O
running	O
.	O
</s>
<s>
Linux	B-Application
malware	I-Application
can	O
also	O
be	O
detected	O
(	O
and	O
analyzed	O
)	O
using	O
memory	O
forensics	O
tools	O
,	O
such	O
as	O
:	O
</s>
<s>
The	O
following	O
is	O
a	O
partial	O
list	O
of	O
known	O
Linux	B-Application
malware	I-Application
.	O
</s>
<s>
However	O
,	O
few	O
if	O
any	O
are	O
in	O
the	O
wild	O
,	O
and	O
most	O
have	O
been	O
rendered	O
obsolete	O
by	O
Linux	B-Application
updates	O
or	O
were	O
never	O
a	O
threat	O
.	O
</s>
<s>
Linux.Remaiten	O
–	O
a	O
threat	O
targeting	O
the	B-Operating_System
Internet	I-Operating_System
of	I-Operating_System
things	I-Operating_System
.	O
</s>
<s>
Mirai	B-Language
(	O
malware	O
)	O
–	O
a	O
DDoS	O
botnet	B-Architecture
spreads	O
through	O
telnet	O
service	O
and	O
designed	O
to	O
infect	O
Internet	B-Operating_System
of	I-Operating_System
Things	I-Operating_System
(	O
IoT	B-Operating_System
)	O
.	O
</s>
<s>
GafGyt/BASHLITE/Qbot	O
–	O
a	O
DDoS	O
botnet	B-Architecture
spreads	O
through	O
SSH	O
and	O
Telnet	O
service	O
weak	O
passwords	O
,	O
firstly	O
discovered	O
during	O
bash	O
Shellshock	O
vulnerability	O
.	O
</s>
<s>
LuaBot	O
–	O
a	O
botnet	B-Architecture
coded	O
with	O
modules	O
component	O
in	O
Lua	O
programming	O
language	O
,	O
cross-compiled	O
in	O
C	O
wrapper	O
with	O
LibC	O
,	O
it	O
aims	O
for	O
Internet	B-Operating_System
of	I-Operating_System
Things	I-Operating_System
in	O
ARM	O
,	O
MIPS	O
and	O
PPC	O
architectures	O
,	O
with	O
the	O
usage	O
to	O
DDoS	O
,	O
spreads	O
Mirai	B-Language
(	O
malware	O
)	O
or	O
selling	O
proxy	O
access	O
to	O
the	O
cyber	O
crime	O
.	O
</s>
<s>
Hydra	O
,	O
Aidra	O
,	O
LightAidra	O
and	O
NewAidra	O
–	O
another	O
form	O
of	O
a	O
powerful	O
IRC	O
botnet	B-Architecture
that	O
infects	O
Linux	B-Application
boxes	I-Application
.	O
</s>
<s>
EnergyMech	O
2.8	O
overkill	O
mod	O
(	O
Linux/Overkill	O
)	O
–	O
a	O
long	O
last	O
botnet	B-Architecture
designed	O
to	O
infect	O
servers	O
with	O
its	O
bot	O
and	O
operated	O
through	O
IRC	O
protocol	O
for	O
the	O
DDoS	O
and	O
spreading	O
purpose	O
.	O
</s>
