20
either
runs
the
source
codes
directly
or
translates the
source
codes
into
efficient
transitional
code
before
it
is
executed.
It
is
considered to
be
higher
level
than
normal
programming
languages. One of
most well-known scripting
language
used
until today
is
Perl
language. Perl
is
a
powerful
high-level scripting
language
used
for
various
intentions.
In
this
thesis,
I
intend
to
use
Perl
scripting language for
two
main
purposes:
making
scripts
that
can
be
run
as
denial-of-service (DoS)
attacks
and
making
administrative scripts that can be
run
by
the IPS
to
operate automation procedures, such
as setting
up or re-configurating
firewalls or routers
to
block the
attacks or blocking
the
attacks based upon the script itself.
1. Fork bomb
#!/usr/bin/perl
fork while 1;
2. Exhausting computer’s CPU
#!/usr/bin/perl
for (1..100) { fork or last }
1
while ++$i
3. Using up RAM memory
#!/usr/bin/perl
for (1..20) { fork or last }
while(++$i) { fh{$i} = "X" x 0xff; }
Figure 4 – Examples of Perl scripts used for simple DoS attack
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