<s>
BGP	B-Protocol
hijacking	I-Protocol
(	O
sometimes	O
referred	O
to	O
as	O
prefix	B-Protocol
hijacking	I-Protocol
,	O
route	B-Protocol
hijacking	I-Protocol
or	O
IP	B-Protocol
hijacking	I-Protocol
)	O
is	O
the	O
illegitimate	O
takeover	O
of	O
groups	O
of	O
IP	B-Protocol
addresses	I-Protocol
by	O
corrupting	O
Internet	O
routing	B-Protocol
tables	I-Protocol
maintained	O
using	O
the	O
Border	B-Protocol
Gateway	I-Protocol
Protocol	I-Protocol
(	O
BGP	B-Protocol
)	O
.	O
</s>
<s>
The	O
Internet	O
is	O
a	O
global	O
network	O
in	O
enabling	O
any	O
connected	O
host	O
,	O
identified	O
by	O
its	O
unique	O
IP	B-Protocol
address	I-Protocol
,	O
to	O
talk	O
to	O
any	O
other	O
,	O
anywhere	O
in	O
the	O
world	O
.	O
</s>
<s>
To	O
do	O
this	O
,	O
each	O
router	O
must	O
be	O
regularly	O
supplied	O
with	O
up-to-date	O
routing	B-Protocol
tables	I-Protocol
.	O
</s>
<s>
At	O
the	O
global	O
level	O
,	O
individual	O
IP	B-Protocol
addresses	I-Protocol
are	O
grouped	O
together	O
into	O
prefixes	O
.	O
</s>
<s>
These	O
prefixes	O
will	O
be	O
originated	O
,	O
or	O
owned	O
,	O
by	O
an	O
autonomous	B-Architecture
system	I-Architecture
(	O
AS	O
)	O
and	O
the	O
routing	B-Protocol
tables	I-Protocol
between	O
ASes	O
are	O
maintained	O
using	O
the	O
Border	B-Protocol
Gateway	I-Protocol
Protocol	I-Protocol
(	O
BGP	B-Protocol
)	O
.	O
</s>
<s>
A	O
group	O
of	O
networks	O
that	O
operates	O
under	O
a	O
single	O
external	O
routing	O
policy	O
is	O
known	O
as	O
an	O
autonomous	B-Architecture
system	I-Architecture
.	O
</s>
<s>
For	O
example	O
,	O
Sprint	O
,	O
Verizon	B-Application
,	O
and	O
AT&T	O
each	O
are	O
an	O
AS	O
.	O
</s>
<s>
BGP	B-Protocol
is	O
the	O
standard	O
routing	O
protocol	O
used	O
to	O
exchange	O
information	O
about	O
IP	O
routing	O
between	O
autonomous	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
Each	O
AS	O
uses	O
BGP	B-Protocol
to	O
advertise	O
prefixes	O
that	O
it	O
can	O
deliver	O
traffic	O
to	O
.	O
</s>
<s>
Although	O
security	O
extensions	O
are	O
available	O
for	O
BGP	B-Protocol
,	O
and	O
third-party	O
route	O
DB	O
resources	O
exist	O
for	O
validating	O
routes	O
,	O
by	O
default	O
the	O
BGP	B-Protocol
protocol	O
is	O
designed	O
to	O
trust	O
all	O
route	O
announcements	O
sent	O
by	O
peers	O
,	O
and	O
few	O
ISPs	O
rigorously	O
enforce	O
checks	O
on	O
BGP	B-Protocol
sessions	I-Protocol
.	O
</s>
<s>
IP	B-Protocol
hijacking	I-Protocol
can	O
occur	O
deliberately	O
or	O
by	O
accident	O
in	O
one	O
of	O
several	O
ways	O
:	O
</s>
<s>
Typically	O
ISPs	O
filter	O
BGP	B-Protocol
traffic	O
,	O
allowing	O
BGP	B-Protocol
advertisements	O
from	O
their	O
downstream	O
networks	O
to	O
contain	O
only	O
valid	O
IP	O
space	O
.	O
</s>
<s>
The	O
Resource	B-Protocol
Public	I-Protocol
Key	I-Protocol
Infrastructure	I-Protocol
(	O
RPKI	B-Protocol
)	O
is	O
designed	O
to	O
authenticate	O
route	O
origins	O
via	O
cryptographic	O
certificate	O
chains	O
demonstrating	O
address	O
block	O
range	O
ownership	O
,	O
but	O
is	O
not	O
widely	O
deployed	O
yet	O
.	O
</s>
<s>
Once	O
deployed	O
,	O
IP	B-Protocol
hijacking	I-Protocol
through	O
errant	O
issues	O
at	O
the	O
origin	O
(	O
via	O
both	O
accident	O
or	O
intent	O
)	O
should	O
be	O
detectable	O
and	O
filterable	O
.	O
</s>
<s>
IP	B-Protocol
hijacking	I-Protocol
is	O
sometimes	O
used	O
by	O
malicious	O
users	O
to	O
obtain	O
IP	B-Protocol
addresses	I-Protocol
for	O
use	O
in	O
spamming	O
or	O
a	O
distributed	O
denial-of-service	O
(	O
DDoS	O
)	O
attack	O
.	O
</s>
<s>
When	O
a	O
router	O
promulgates	O
flawed	O
BGP	B-Protocol
routing	O
information	O
,	O
whether	O
that	O
action	O
is	O
intentional	O
or	O
accidental	O
,	O
it	O
is	O
defined	O
by	O
the	O
Internet	O
Engineering	O
Task	O
Force	O
(	O
IETF	O
)	O
in	O
RFC	O
7908	O
as	O
a	O
"	O
route	O
leak	O
"	O
.	O
</s>
<s>
That	O
is	O
,	O
an	O
announcement	O
from	O
an	O
Autonomous	B-Architecture
System	I-Architecture
(	O
AS	O
)	O
of	O
a	O
learned	O
BGP	B-Protocol
route	O
to	O
another	O
AS	O
is	O
in	O
violation	O
of	O
the	O
intended	O
policies	O
of	O
the	O
receiver	O
,	O
the	O
sender	O
,	O
and/or	O
one	O
of	O
the	O
ASes	O
along	O
the	O
preceding	O
AS	O
path.	O
"	O
</s>
<s>
Such	O
leaks	O
are	O
possible	O
because	O
of	O
a	O
long-standing	O
"	O
…	O
systemic	O
vulnerability	O
of	O
the	O
Border	B-Protocol
Gateway	I-Protocol
Protocol	I-Protocol
routing	O
system	O
…	O
"	O
</s>
<s>
Like	O
the	O
TCP	B-Protocol
reset	I-Protocol
attack	I-Protocol
,	O
session	B-Protocol
hijacking	I-Protocol
involves	O
intrusion	O
into	O
an	O
ongoing	O
BGP	B-Protocol
session	I-Protocol
,	O
i.e.	O
,	O
the	O
attacker	O
successfully	O
masquerades	O
as	O
one	O
of	O
the	O
peers	O
in	O
a	O
BGP	B-Protocol
session	I-Protocol
,	O
and	O
requires	O
the	O
same	O
information	O
needed	O
to	O
accomplish	O
the	O
reset	O
attack	O
.	O
</s>
<s>
The	O
difference	O
is	O
that	O
a	O
session	B-Protocol
hijacking	I-Protocol
attack	O
may	O
be	O
designed	O
to	O
achieve	O
more	O
than	O
simply	O
bringing	O
down	O
a	O
session	O
between	O
BGP	B-Protocol
peers	O
.	O
</s>
<s>
By	O
default	O
EBGP	B-Protocol
peers	O
will	O
attempt	O
to	O
add	O
all	O
routes	O
received	O
by	O
another	O
peer	O
into	O
the	O
device	O
's	O
routing	B-Protocol
table	I-Protocol
and	O
will	O
then	O
attempt	O
to	O
advertise	O
nearly	O
all	O
of	O
these	O
routes	O
to	O
other	O
EBGP	B-Protocol
peers	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
customer	O
with	O
a	O
Cisco	O
router	O
peering	O
with	O
say	O
AT&T	O
and	O
Verizon	B-Application
and	O
using	O
no	O
filtering	O
will	O
automatically	O
attempt	O
to	O
link	O
the	O
two	O
major	O
carriers	O
,	O
which	O
could	O
cause	O
the	O
providers	O
to	O
prefer	O
sending	O
some	O
or	O
all	O
traffic	O
through	O
the	O
customer	O
(	O
on	O
perhaps	O
a	O
T1	O
)	O
,	O
instead	O
of	O
using	O
high-speed	O
dedicated	O
links	O
.	O
</s>
<s>
However	O
,	O
any	O
ISP	O
not	O
filtering	O
customer	O
advertisements	O
can	O
allow	O
errant	O
information	O
to	O
be	O
advertised	O
into	O
the	O
global	O
routing	B-Protocol
table	I-Protocol
where	O
it	O
can	O
affect	O
even	O
the	O
large	O
Tier-1	O
providers	O
.	O
</s>
<s>
The	O
concept	O
of	O
BGP	B-Protocol
hijacking	I-Protocol
revolves	O
around	O
locating	O
an	O
ISP	O
that	O
is	O
not	O
filtering	O
advertisements	O
(	O
intentionally	O
or	O
otherwise	O
)	O
or	O
locating	O
an	O
ISP	O
whose	O
internal	O
or	O
ISP-to-ISP	O
BGP	B-Protocol
session	I-Protocol
is	O
susceptible	O
to	O
a	O
man-in-the-middle	O
attack	O
.	O
</s>
<s>
Also	O
,	O
in	O
February	O
2008	O
,	O
a	O
large	O
portion	O
of	O
YouTube	B-General_Concept
's	O
address	O
space	O
was	O
redirected	O
to	O
Pakistan	O
when	O
the	O
PTA	O
decided	O
to	O
block	O
access	O
to	O
the	O
site	O
from	O
inside	O
the	O
country	O
,	O
but	O
accidentally	O
blackholed	O
the	O
route	O
in	O
the	O
global	O
BGP	B-Protocol
table	O
.	O
</s>
<s>
While	O
filtering	O
and	O
MD5/TTL	O
protection	O
is	O
already	O
available	O
for	O
most	O
BGP	B-Protocol
implementations	O
(	O
thus	O
preventing	O
the	O
source	O
of	O
most	O
attacks	O
)	O
,	O
the	O
problem	O
stems	O
from	O
the	O
concept	O
that	O
ISPs	O
rarely	O
ever	O
filter	O
advertisements	O
from	O
other	O
ISPs	O
,	O
as	O
there	O
is	O
no	O
common	O
or	O
efficient	O
way	O
to	O
determine	O
the	O
list	O
of	O
permissible	O
prefixes	O
each	O
AS	O
can	O
originate	O
.	O
</s>
<s>
The	O
penalty	O
for	O
allowing	O
errant	O
information	O
to	O
be	O
advertised	O
can	O
range	O
from	O
simple	O
filtering	O
by	O
other/larger	O
ISPs	O
to	O
a	O
complete	O
shutdown	O
of	O
the	O
BGP	B-Protocol
session	I-Protocol
by	O
the	O
neighboring	O
ISP	O
(	O
causing	O
the	O
two	O
ISPs	O
to	O
cease	O
peering	O
)	O
,	O
and	O
repeated	O
problems	O
often	O
end	O
in	O
permanent	O
termination	O
of	O
all	O
peering	O
agreements	O
.	O
</s>
<s>
It	O
is	O
also	O
noteworthy	O
that	O
even	O
causing	O
a	O
major	O
provider	O
to	O
block	O
or	O
shutdown	O
a	O
smaller	O
,	O
problematic	O
provider	O
,	O
the	O
global	O
BGP	B-Protocol
table	O
will	O
often	O
reconfigure	O
and	O
reroute	O
the	O
traffic	O
through	O
other	O
available	O
routes	O
until	O
all	O
peers	O
take	O
action	O
,	O
or	O
until	O
the	O
errant	O
ISP	O
fixes	O
the	O
problem	O
at	O
the	O
source	O
.	O
</s>
<s>
One	O
useful	O
offshoot	O
of	O
this	O
concept	O
is	O
called	O
BGP	B-Protocol
anycasting	O
and	O
is	O
frequently	O
used	O
by	O
root	O
DNS	O
servers	O
to	O
allow	O
multiple	O
servers	O
to	O
use	O
the	O
same	O
IP	B-Protocol
address	I-Protocol
,	O
providing	O
redundancy	O
and	O
a	O
layer	O
of	O
protection	O
against	O
DoS	O
attacks	O
without	O
publishing	O
hundreds	O
of	O
server	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
February	O
24	O
,	O
2008	O
:	O
Pakistan	O
's	O
attempt	O
to	O
block	O
YouTube	B-General_Concept
access	O
within	O
their	O
country	O
takes	O
down	O
YouTube	B-General_Concept
entirely	O
.	O
</s>
<s>
November	O
11	O
,	O
2008	O
:	O
The	O
Brazilian	O
ISP	O
CTBC	O
-	O
Companhia	O
de	O
Telecomunicações	O
do	O
Brasil	O
Central	O
leaked	O
their	O
internal	O
table	O
into	O
the	O
global	O
BGP	B-Protocol
table	O
.	O
</s>
<s>
ROS	O
and	O
the	O
Hacking	O
Team	O
worked	O
with	O
the	O
Italian	O
network	O
operator	O
Aruba	O
S.p.A.	O
(	O
AS31034	O
)	O
to	O
get	O
the	O
prefix	O
announced	O
in	O
BGP	B-Protocol
in	O
order	O
to	O
regain	O
access	O
to	O
the	O
control	O
server	O
.	O
</s>
<s>
April	O
2017	O
:	O
Russian	O
telecommunication	O
company	O
Rostelecom	O
(	O
AS12389	O
)	O
originated	O
37	O
prefixes	O
for	O
numerous	O
other	O
Autonomous	B-Architecture
Systems	I-Architecture
.	O
</s>
<s>
December	O
2017	O
:	O
Eighty	O
high-traffic	O
prefixes	O
normally	O
announced	O
by	O
Google	B-Application
,	O
Apple	O
,	O
Facebook	B-Application
,	O
Microsoft	O
,	O
Twitch	O
,	O
NTT	O
Communications	O
,	O
Riot	O
Games	O
,	O
and	O
others	O
,	O
were	O
announced	O
by	O
a	O
Russian	O
AS	O
,	O
DV-LINK-AS	O
(	O
AS39523	O
)	O
.	O
</s>
<s>
April	O
2018	O
:	O
Roughly	O
1300	O
IP	B-Protocol
addresses	I-Protocol
within	O
Amazon	B-Application
Web	I-Application
Services	I-Application
space	O
,	O
dedicated	O
to	O
Amazon	B-Protocol
Route	I-Protocol
53	I-Protocol
,	O
were	O
hijacked	O
by	O
eNet	O
(	O
or	O
a	O
customer	O
thereof	O
)	O
,	O
an	O
ISP	O
in	O
Columbus	O
,	O
Ohio	O
.	O
</s>
<s>
July	O
2018	O
:	O
Iran	O
Telecommunication	O
Company	O
(	O
AS58224	O
)	O
originated	O
10	O
prefixes	O
of	O
Telegram	B-Application
Messenger	I-Application
.	O
</s>
<s>
November	O
2018	O
:	O
US-based	O
China	O
Telecom	O
site	O
originated	O
Google	B-Application
addresses	O
.	O
</s>
<s>
April	O
2021	O
:	O
Large	O
BGP	B-Protocol
routing	O
leak	O
out	O
of	O
India	O
:	O
over	O
30,000	O
BGP	B-Protocol
prefixes	I-Protocol
hijacked	O
via	O
Vodafone	O
Idea	O
Ltd	O
(	O
AS55410	O
)	O
causing	O
13X	O
spike	O
in	O
inbound	O
traffic	O
.	O
</s>
<s>
Prefixes	O
were	O
from	O
around	O
the	O
globe	O
but	O
mostly	O
US	O
including	O
Google	B-Application
,	O
Microsoft	O
,	O
Akamai	O
,	O
and	O
Cloudflare	O
.	O
</s>
<s>
February	O
2022	O
:	O
Attackers	O
hijacked	O
BGP	B-Protocol
prefixes	I-Protocol
that	O
belonged	O
to	O
a	O
South	O
Korean	O
cryptocurrency	O
platform	O
,	O
and	O
then	O
issued	O
a	O
certificate	O
on	O
the	O
domain	O
via	O
ZeroSSL	O
to	O
serve	O
a	O
malicious	O
JavaScript	O
file	O
,	O
stealing	O
$1.9	O
million	O
worth	O
of	O
cryptocurrency	O
.	O
</s>
