Prefix hijacking, how to prevent and fix currently

Doug Madory dmadory at
Wed Sep 3 17:27:14 UTC 2014

This blog post furthers this discussion, but it would have been appropriate to cite my original analysis explicitly, rather than simply citing "some discussion on Nanog recently."

If we want to foster a community where people share expertise on this list, fully citing others' work is essential, as in any professional or academic setting.

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

On Aug 31, 2014, at 2:04 PM, Doug Madory <dmadory at> 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

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