nanog mailing list archives

Re: Prefix hijacking, how to prevent and fix currently


From: Doug Madory <dmadory () renesys com>
Date: Fri, 5 Sep 2014 12:12:48 -0400

Hi Nick, All,

Thanks for the links. I'm glad to know people are working on this. I don't think anyone was suggesting that this was a 
new phenomenon. 

Someone wrote to this list about a particular incident and I shared details about how this was part of a larger IP 
squatting operation. Unique from other on-going IP squatting incidents that I'm aware of, this one was rather unique in 
its use of two unused ASNs to quickly cycle through various prefixes of (mostly) unused address space.

http://seclists.org/nanog/2014/Aug/513  (Aug 31)

It was disappointing to see someone claim the discovery of this IP squatting operation three days later without a 
reference to my detailed write-up in this public forum. This had been going for months, but only after I explained what 
had happened could this "discovery" take place.

http://www.bgpmon.net/using-bgp-data-to-find-spammers/  (Sep 3)

What is most interesting is that shortly before I wrote my email, the IP squatting operation had changed tactics. 
Although there are still some stale routes in circulation, the "57756 {43239, {3.721}" format is no longer the format 
being used. 

Since Saturday, the IP squatting operation has moved to the following route format:

        ... 44050 197598 {49121, 197794}        prefix

By the time of Andree's blog post on Wednesday, this new route format had been the main tactic for four days. He didn't 
pick up on the change - perhaps because I hadn't caught the change by the time I wrote my email this weekend. Maybe he 
can "discover" it now.

BTW, these routes are being universally accepted, so whatever technique we think we're employing to filter routes like 
this, it isn't working. 

Doug Madory
603-643-9300 x115
Hanover, NH
"The Internet Intelligence Authority"

On Sep 4, 2014, at 2:47 PM, Nick Feamster <feamster () cc gatech edu> wrote:

Hi Doug, All,

We’ve seen similar things, including hijacks of less specific IP prefixes (even /8s), correlated with spam behavior.  

We presented on this at NANOG 35:
http://nanog.org/meetings/nanog36/presentations/feamster.pdf

Slide 4 shows a short-lived BGP announcement for IP space that was the source of spam.  Interestingly, many of the 
short-lived annoucements that we observed were /8s.  Subsequent slides explain why.  Subsequent slides explain these 
observations in more detail, and we had a paper in SIGCOMM’06 describing this activity in more detail:
http://www.cc.gatech.edu/~feamster/papers/p396-ramachandran.pdf

We have a couple of pieces of follow-up work:
- It turns out that you can use BGP dynamics as features to design filters for spam and other attack traffic (we have 
a couple of papers on this)
- Some of these observable dynamics are also useful for establishing AS reputation (a la Hostexploit) - we have some 
ongoing work here

Happy to talk more, either on-list or off-list.

Cheers,
-Nick

On Aug 31, 2014, at 2:04 PM, Doug Madory <dmadory () renesys com> wrote:

FWIW, this is from an IP squatting operation I came across in recent weeks. I encounter these things regularly in 
the course of working with BGP data - probably others do too. Usually I look up the ASN or prefix and often it has 
already been added to someone's spam source list. When I see that, I assume the "system is working" and move on.

In this case, starting late Jun, we have seen IP address ranges from around the world (most ranges are unused, 
sometimes hijacked space) announced by one of two (formerly unused) ASNs and routed through another formerly unused 
ASN, 57756, then on to Anders (AS39792) and out to the Internet in the following form:

     ... 39792 57756 {3.721, 43239}  prefix

The prefixes are only routed for an hour or two before it moves on to the next range of IP address space. Not sure 
if this is for spam or something else. Either way, it is probably associated with something bad. Earlier this month 
I reached out to a contact at Anders in Russia and gave him some details about what was happening. I didn't get a 
response, but within a couple of days the routing (mostly) shifted from Anders to through Petersburg Internet 
Network (AS44050). I have no idea if this was due to my email. The day it moved to PIN I sent similar emails to 
addresses I could find at PIN, but haven't seen any response. Now the these routes take one of two forms:

     ... 39792 57756 {3.721, 43239}  prefix

Or

     ... 44050 57756 {3.721, 43239}  prefix

This is mostly routed through Cogent (AS174), but Anders (AS39792) also has a lot of peers. I would advise that 
people treat any route coming through AS57756 is probably bad. AS57756 doesn't originate anything and hasn't since 
28-Jun when it very briefly hijacked some NZ space.

Also, Pierre-Antoine Vervier from Symantec gave a good talk at NANOG in Feb about IP squatting for spam generation. 
Pierre and I have since compared notes on this topic.

-Doug Madory

----- Original Message -----
From: "Tarun Dua" <lists () tarundua net>
To: nanog () nanog org
Sent: Thursday, August 28, 2014 12:55:25 PM
Subject: Prefix hijacking, how to prevent and fix currently

AS Number 43239
AS Name SPETSENERGO-AS SpetsEnergo Ltd.

Has started hijacking our IPv4 prefix, while this prefix was NOT in
production, it worries us that it was this easy for someone to hijack
it.

http://bgp.he.net/AS43239#_prefixes

103.20.212.0/22 <- This belongs to us.

103.238.232.0/22 KNS Techno Integrators Pvt. Ltd.
193.43.33.0/24 hydrocontrol S.C.R.L.
193.56.146.0/24 TRAPIL - Societe des Transports Petroliers par Pipeline

Where do we complain to get this fixed.

-Tarun
AS132420




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