(Jul)ledighet - risk för att "buset" ökar
Halloj, Vi har inte sett så mycket “bus” mot vår DNS-infrastruktur på väldigt länge, men det verkar börja hända saker nu när långledighet nalkas. Inget allvarligt, men det är lite anmärkningsvärt att vi fått över 10000 “träffar” (som resulterar i automatisk ratelimit installeras) från en Telia IP samt från Cloudflare IPs nu under det närmsta dygnet. När jag skriver “träffar”, så räknar vi en “träff” när en IP-adress skjuter minst 30 qps som alla resulterar i NXDOMAIN, under minst ett pars sekunders sammanhängande tidspann (Så totalt pratar vi om över 2+ miljoner frågor som resulterat i NXDOMAIN) De IP-adresser som vi ser som står ut är: Telia 78.66.132.30 - redan på 2 st blocklistor Samt Cloudflare - verkar inte listade på någon blocklista 2400:cb00:128:1024::a29e:b4e0 2400:cb00:128:1024::a29e:b4e1 2400:cb00:128:1024::a29e:b4e2 162.158.180.224 162.158.180.225 162.158.180.226 Så, kort och gott undrar jag om någon annan börjat se likande saker/ trender öka nu? (Ni svara mig utanför listan om ni inte vill säga det “öppet") God Jul så länge Mvh, /P
Hej "Fredrik Pettai via Ns.se" <ns.se@lists.iis.se> writes:
Vi har inte sett så mycket “bus” mot vår DNS-infrastruktur på väldigt länge, men det verkar börja hända saker nu när långledighet nalkas.
At group.one (one.com) I have not noticed any particular increase in "internet noise" against our DNS servers over the past weeks. Do you see any pattern in queries being made that could give you a hint about what is going on? E.g. is it towards zones hosted in your DNS servers? Which kind of records are they looking for? Are there any patterns in the names they query for? Best regards, Jacob
Hi Jacob,
On 20 Dec 2024, at 08:02, Jacob Bunk Nielsen via Ns.se <ns.se@lists.iis.se> wrote:
Hej
"Fredrik Pettai via Ns.se" <ns.se@lists.iis.se> writes:
Vi har inte sett så mycket “bus” mot vår DNS-infrastruktur på väldigt länge, men det verkar börja hända saker nu när långledighet nalkas.
At group.one (one.com) I have not noticed any particular increase in "internet noise" against our DNS servers over the past weeks.
Do you see any pattern in queries being made that could give you a hint about what is going on? E.g. is it towards zones hosted in your DNS servers?
We don’t log queries by default, we only log all issues/errors and policy decisions. Our “manual checks" on incoming traffic from the Cloudflare IPs was towards a specific zone that we are secondary for. (The primary zone owner got hit by even more Cloudflare IPs, probably because the don’t do any automatic policy actions on their infrastructure).
Which kind of records are they looking for? Are there any patterns in the names they query for?
Real names & words in the zone or subdomain(s) of the zone, as far as we could see from our manual checks. And the name server stats didn't show any broken / illegal queries either. Since we don’t log queries (for privacy reasons), we can only guess they were updating a catalog of free domain names. Perhaps this is more of an issue for TLDs? Only we haven’t seen this before… Re, /P
Best regards, Jacob -- Ns.se mailing list -- ns.se@lists.iis.se To unsubscribe send an email to ns.se-leave@lists.iis.se
Hi Frederik "Fredrik Pettai via Ns.se" <ns.se@lists.iis.se> writes:
On 20 Dec 2024, at 08:02, Jacob Bunk Nielsen via Ns.se <ns.se@lists.iis.se> wrote:
Do you see any pattern in queries being made that could give you a hint about what is going on? E.g. is it towards zones hosted in your DNS servers?
We don’t log queries by default, we only log all issues/errors and policy decisions.
We log a small statistical sample of queries to be able to investigate what we get a lot of. If you can live with the privacy implications, I can highly recommend this for later investigation.
Which kind of records are they looking for? Are there any patterns in the names they query for?
Real names & words in the zone or subdomain(s) of the zone, as far as we could see from our manual checks. And the name server stats didn't show any broken / illegal queries either.
Seems like a standard pseudo-random subdomain attack to me.
Since we don’t log queries (for privacy reasons), we can only guess they were updating a catalog of free domain names. Perhaps this is more of an issue for TLDs? Only we haven’t seen this before…
They would only hit your name servers for domains that are delegated to your servers, right? So looking up stuff like example.sunet.se would only really be useful as part of some form of attack, I believe. We see these sort of attacks regularly. Best regards, Jacob
participants (2)
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Fredrik Pettai -
Jacob Bunk Nielsen