<s>
Ettercap	B-Language
is	O
a	O
free	B-License
and	I-License
open	I-License
source	I-License
network	O
security	O
tool	O
for	O
man-in-the-middle	O
attacks	O
on	O
a	O
LAN	B-General_Concept
.	O
</s>
<s>
It	O
runs	O
on	O
various	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
including	O
Linux	B-Application
,	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
BSD	B-Operating_System
and	O
Solaris	B-Application
,	O
and	O
on	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Ettercap	B-Language
works	O
by	O
putting	O
the	O
network	O
interface	O
into	O
promiscuous	B-Protocol
mode	I-Protocol
and	O
by	O
ARP	O
poisoning	O
the	O
target	O
machines	O
.	O
</s>
<s>
Ettercap	B-Language
has	O
plugin	O
support	O
so	O
that	O
the	O
features	O
can	O
be	O
extended	O
by	O
adding	O
new	O
plugins	O
.	O
</s>
<s>
Ettercap	B-Language
supports	O
active	O
and	O
passive	O
dissection	O
of	O
many	O
protocols	O
(	O
including	O
ciphered	O
ones	O
)	O
and	O
provides	O
many	O
features	O
for	O
network	O
and	O
host	O
analysis	O
.	O
</s>
<s>
Ettercap	B-Language
offers	O
four	O
modes	O
of	O
operation	O
:	O
</s>
<s>
MAC-based	O
:	O
packets	O
are	O
filtered	O
based	O
on	O
MAC	O
address	O
,	O
useful	O
for	O
sniffing	B-Protocol
connections	O
through	O
a	O
gateway	B-Application
.	O
</s>
<s>
ARP-based	O
:	O
uses	O
ARP	O
poisoning	O
to	O
sniff	O
on	O
a	O
switched	O
LAN	B-General_Concept
between	O
two	O
hosts	O
(	O
full-duplex	O
)	O
.	O
</s>
<s>
PublicARP-based	O
:	O
uses	O
ARP	O
poisoning	O
to	O
sniff	O
on	O
a	O
switched	O
LAN	B-General_Concept
from	O
a	O
victim	O
host	O
to	O
all	O
other	O
hosts	O
(	O
half-duplex	O
)	O
.	O
</s>
<s>
Character	O
injection	O
into	O
an	O
established	O
connection	O
:	O
characters	O
can	O
be	O
injected	O
into	O
a	O
server	B-Application
(	O
emulating	O
commands	O
)	O
or	O
to	O
a	O
client	B-Protocol
(	O
emulating	O
replies	O
)	O
while	O
maintaining	O
a	O
live	O
connection	O
.	O
</s>
<s>
SSH1	B-Protocol
support	O
:	O
the	O
sniffing	B-Protocol
of	O
a	O
username	O
and	O
password	O
,	O
and	O
even	O
the	O
data	O
of	O
an	O
SSH1	B-Protocol
connection	O
.	O
</s>
<s>
Ettercap	B-Language
is	O
the	O
first	O
software	O
capable	O
of	O
sniffing	B-Protocol
an	O
SSH	B-Protocol
connection	O
in	O
full	O
duplex	O
.	O
</s>
<s>
HTTPS	B-Protocol
support	O
:	O
the	O
sniffing	B-Protocol
of	O
HTTP	B-Protocol
SSL	B-Protocol
secured	O
data	O
—	O
even	O
when	O
the	O
connection	O
is	O
made	O
through	O
a	O
proxy	B-Application
.	O
</s>
<s>
Remote	O
traffic	O
through	O
a	O
GRE	B-Protocol
tunnel	I-Protocol
:	O
the	O
sniffing	B-Protocol
of	O
remote	O
traffic	O
through	O
a	O
GRE	B-Protocol
tunnel	I-Protocol
from	O
a	O
remote	O
Cisco	O
router	B-Protocol
,	O
and	O
perform	O
a	O
man-in-the-middle	O
attack	O
on	O
it	O
.	O
</s>
<s>
Plug-in	O
support	O
:	O
creation	O
of	O
custom	O
plugins	O
using	O
Ettercap	B-Language
's	O
API	B-Application
.	O
</s>
<s>
Packet	O
filtering/dropping	O
:	O
setting	O
up	O
a	O
filter	O
that	O
searches	O
for	O
a	O
particular	O
string	O
(	O
or	O
hexadecimal	O
sequence	O
)	O
in	O
the	O
TCP	B-Protocol
or	O
UDP	B-Protocol
payload	O
and	O
replaces	O
it	O
with	O
a	O
custom	O
string/sequence	O
of	O
choice	O
,	O
or	O
drops	O
the	O
entire	O
packet	O
.	O
</s>
<s>
TCP/IP	B-Protocol
stack	I-Protocol
fingerprinting	I-Protocol
:	O
determine	O
the	O
OS	B-General_Concept
of	O
the	O
victim	O
host	O
and	O
its	O
network	O
adapter	O
.	O
</s>
<s>
Passive	O
scanning	O
of	O
the	O
LAN	B-General_Concept
:	O
retrieval	O
of	O
information	O
about	O
hosts	O
on	O
the	O
LAN	B-General_Concept
,	O
their	O
open	O
ports	B-Protocol
,	O
the	O
version	O
numbers	O
of	O
available	O
services	B-General_Concept
,	O
the	O
type	O
of	O
the	O
host	O
(	O
gateway	B-Application
,	O
router	B-Protocol
or	O
simple	O
PC	B-Device
)	O
and	O
estimated	O
distances	O
in	O
number	O
of	O
hops	O
.	O
</s>
<s>
Hijacking	O
of	O
DNS	B-Protocol
requests	O
.	O
</s>
<s>
Ettercap	B-Language
also	O
has	O
the	O
ability	O
to	O
actively	O
or	O
passively	O
find	O
other	O
poisoners	O
on	O
the	O
LAN	B-General_Concept
.	O
</s>
