Hi folks, Recently I read a post regarding the recent incident of Celer Network and noticed a very interesting and successful BGP hijacking towards AS16509. The attacker AS209243 added AS16509 to their AS-SET and a more specific route object for the /24 where the victim's website is in ALTDB: (Below is our IRRd4 server NRTM logging, UTC timezone) irrd.log-20220817.gz:31106270-ADD 96126 irrd.log-20220817.gz:31106280- irrd.log-20220817.gz:31106281-as-set: AS-SET209243 irrd.log-20220817.gz:31106306-descr: quickhost set irrd.log-20220817.gz:31106332-members: AS209243, AS16509 irrd.log-20220817.gz:31106362:mnt-by: MAINT-QUICKHOSTUK irrd.log-20220817.gz:31106392-changed: crussell@quickhostuk.net 20220816 irrd.log-20220817.gz:31106438-source: ALTDB irrd.log-20220817.gz:31147549-ADD 96127 irrd.log-20220817.gz:31147559- irrd.log-20220817.gz:31147560-route: 44.235.216.0/24 irrd.log-20220817.gz:31147588-descr: route irrd.log-20220817.gz:31147606-origin: AS16509 irrd.log-20220817.gz:31147626:mnt-by: MAINT-QUICKHOSTUK irrd.log-20220817.gz:31147656-changed: crussell@quickhostuk.net 20220816 irrd.log-20220817.gz:31147702-source: ALTDB Then they started announcing the prefix ... under another AWS ASN (AS14618) I guess AS1299 Arelion doesn't check if the origin AS of an announcement is in the customer's AS-SET but it's pretty normal and understandable. https://stat.ripe.net/widget/bgplay#w.resource=44.235.216.0/24&w.ignoreReannouncements=true&w.starttime=1660694458&w.endtime=1661032798&w.rrcs=0&w.instant=null&w.type=bgp Type: A > announce Involving: 44.235.216.0/24 Short description: The new route 34854 1299 209243 14618 has been announced Path: 34854, 1299, 209243, 14618, Community: 1299:35000,34854:3001 Date and time: 2022-08-17 19:39:50 Collected by: 00-2.56.11.1 Hjacking didn't last too long. AWS started announcing a more specific announcement to prevent hijacking around 3 hours later. Kudos to Amazon's security team :-) Type: A > announce Involving: 44.235.216.0/24 Short description: The new route 58057 34549 5511 1299 16509 has been announced Path: 58057, 34549, 5511, 1299, 16509, Community: 5511:521,5511:666,5511:710,5511:5511,34549:100,34549:5511 Date and time: 2022-08-17 23:08:47 Collected by: 00-194.50.92.251 The attacker cleaned up the IRR objects on 17 Aug and surprisingly no one seems to notice them ... irrd.log-20220819.gz:26517714-ADD 96196 irrd.log-20220819.gz:26517724- irrd.log-20220819.gz:26517725:as-set: AS-SET209243 irrd.log-20220819.gz:26517750-descr: quickhost set irrd.log-20220819.gz:26517776-members: AS209243, AS35437, AS37497 irrd.log-20220819.gz:26517815-mnt-by: MAINT-QUICKHOSTUK irrd.log-20220819.gz:26517845-changed: crussell@quickhostuk.net 20220817 irrd.log-20220819.gz:26517891-source: ALTDB irrd.log-20220819.gz:26517910-DEL 96197 irrd.log-20220819.gz:26517920- irrd.log-20220819.gz:26517921-route: 44.235.216.0/24 irrd.log-20220819.gz:26517949-descr: route irrd.log-20220819.gz:26517967-origin: AS16509 irrd.log-20220819.gz:26517987-mnt-by: MAINT-QUICKHOSTUK irrd.log-20220819.gz:26518017-changed: crussell@quickhostuk.net 20220816 irrd.log-20220819.gz:26518063-source: ALTDB Nowadays hijacking a service by forging AS path is pretty easy and RPKI won't be able to solve this (as it validates origin AS and prefixes only) :-( Regards, Siyuan