<s>
Footprinting	B-General_Concept
(	O
also	O
known	O
as	O
reconnaissance	O
)	O
is	O
the	O
technique	O
used	O
for	O
gathering	O
information	O
about	O
computer	O
systems	O
and	O
the	O
entities	O
they	O
belong	O
to	O
.	O
</s>
<s>
When	O
used	O
in	O
the	O
computer	O
security	O
lexicon	O
,	O
"	O
Footprinting	B-General_Concept
"	O
generally	O
refers	O
to	O
one	O
of	O
the	O
pre-attack	O
phases	O
;	O
tasks	O
performed	O
before	O
doing	O
the	O
actual	O
attack	O
.	O
</s>
<s>
Some	O
of	O
the	O
tools	O
used	O
for	O
Footprinting	B-General_Concept
are	O
Sam	B-Application
Spade	I-Application
,	O
nslookup	B-Protocol
,	O
traceroute	B-Protocol
,	O
Nmap	B-Language
and	O
neotrace	O
.	O
</s>
<s>
Footprinting	B-General_Concept
is	O
also	O
used	O
by	O
ethical	O
hackers	O
and	O
penetration	O
testers	O
to	O
find	O
security	O
flaws	O
and	O
vulnerabilities	O
within	O
their	O
own	O
company	O
's	O
network	O
before	O
a	O
malicious	O
hacker	O
does	O
.	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
Footprinting	B-General_Concept
that	O
can	O
be	O
used	O
:	O
active	O
Footprinting	B-General_Concept
and	O
passive	O
Footprinting	B-General_Concept
.	O
</s>
<s>
Active	O
Footprinting	B-General_Concept
is	O
the	O
process	O
of	O
using	O
tools	O
and	O
techniques	O
,	O
such	O
as	O
performing	O
a	O
ping	B-Protocol
sweep	I-Protocol
or	O
using	O
the	O
traceroute	B-Protocol
command	O
,	O
to	O
gather	O
information	O
on	O
a	O
target	O
.	O
</s>
<s>
Active	O
Footprinting	B-General_Concept
can	O
trigger	O
a	O
target	O
's	O
Intrusion	O
Detection	O
System	O
(	O
IDS	O
)	O
and	O
may	O
be	O
logged	O
,	O
and	O
thus	O
requires	O
a	O
level	O
of	O
stealth	O
to	O
successfully	O
do	O
.	O
</s>
<s>
Passive	O
Footprinting	B-General_Concept
is	O
the	O
process	O
of	O
gathering	O
information	O
on	O
a	O
target	O
by	O
innocuous	O
,	O
or	O
,	O
passive	O
,	O
means	O
.	O
</s>
<s>
Browsing	O
the	O
target	O
's	O
website	O
,	O
visiting	O
social	O
media	O
profiles	O
of	O
employees	O
,	O
searching	O
for	O
the	O
website	O
on	O
WHOIS	B-Protocol
,	O
and	O
performing	O
a	O
Google	B-Application
search	O
of	O
the	O
target	O
are	O
all	O
ways	O
of	O
passive	O
Footprinting	B-General_Concept
.	O
</s>
<s>
Passive	O
Footprinting	B-General_Concept
is	O
the	O
stealthier	O
method	O
since	O
it	O
will	O
not	O
trigger	O
a	O
target	O
's	O
IDS	O
or	O
otherwise	O
alert	O
the	O
target	O
of	O
information	O
being	O
gathered	O
.	O
</s>
<s>
WHOIS	B-Protocol
is	O
a	O
web	O
application	O
used	O
to	O
get	O
information	O
about	O
the	O
target	O
website	O
,	O
such	O
as	O
the	O
administrator	O
's	O
e-mail	O
address	O
and	O
details	O
about	O
the	O
registration	O
.	O
</s>
<s>
WHOIS	B-Protocol
is	O
a	O
very	O
large	O
database	O
and	O
contains	O
information	O
of	O
approximately	O
all	O
clearnet	O
websites	O
.	O
</s>
<s>
Search	O
engines	O
such	O
as	O
Google	B-Application
can	O
also	O
be	O
used	O
to	O
gather	O
information	O
about	O
the	O
target	O
system	O
.	O
</s>
<s>
Information	O
can	O
also	O
be	O
gathered	O
using	O
the	O
command	O
Tracert	B-Protocol
(	O
"	O
traceroute	B-Protocol
"	O
)	O
,	O
which	O
is	O
used	O
to	O
trace	O
a	O
path	O
between	O
a	O
user	O
and	O
the	O
target	O
system	O
on	O
the	O
networks	O
.	O
</s>
<s>
In	O
Linux	B-Application
systems	O
,	O
the	O
tracepath	O
and	O
traceroute	B-Protocol
commands	O
are	O
also	O
available	O
for	O
doing	O
traceroute	B-Protocol
operations	O
.	O
</s>
