In the period from 2020-12-04 until 2020-12-10 someone representing AS28753 - Leaseweb Deutschland GmbH, or someone purporting to represent that ASN/company created a set of thirteen (13) new route: entries in the security-free RADB data base: https://pastebin.com/raw/qs9yywFe It appears somewhat more than coincidental that many of these new RADB route entries refer to either(a) legacy IPv4 address blocks in the ARIN region or else (b) unassigned (bogon) IPv4 address space in the ARIN region. A listing of the relevant IPv4 cidrs along with the top-level allocation holders for each CIDR is given in the following table: https://pastebin.com/raw/rnqMXHW0 Although there is some ambiguity regarding the status of the non-US/non-ARIN blocks listed in the above table, my inspection of the relevant WHOIS records for the US/ARIN blocks indicates to me that these are all either (a) abandoned IPv4 legacy blocks or else (b) unassigned ARIN bogons. This strongly suggests that all of the IPv4 address blocks named in all of the relevant RADB rote entries may be, and likely are being squatted on at the present time. Please note however that AS28753 - Leaseweb Deutschland GmbH - is not itself doing any of the squatting. Rather, the squatting is being undertaken by the various ASNs mention in the following active routing summary: 62.182.160.0/21 AS39325 RU Viptelecom LLC 79.173.104.0/21 AS13259 RU Delta Telesystems Ltd. 85.28.48.0/20 AS13259 RU Delta Telesystems Ltd. 85.89.104.0/21 AS13259 RU Delta Telesystems Ltd. 89.187.8.0/21 AS41762 UA PE Logvinov Vladimir Vladimirovich 91.229.148.0/22 AS56968 KZ TemirLan Net Ltd 128.0.80.0/20 AS34498 RU Jilcomservice 199.61.32.0/19 AS9009 GB M247 Ltd 204.229.64.0/19 AS10650 US Extreme Internet 205.134.96.0/19 AS10650 US Extreme Internet 205.148.96.0/19 AS397373 US H4Y Technologies LLC 209.151.96.0/19 AS9009 GB M247 Ltd 216.93.0.0/19 AS9009 GB M247 Ltd Note that AS10650 (Extreme Internet) is itself a legacy abandoned ARIN ASN. It is likely also squatted. It's one and only current upstream, according to bgp.he.net, is AS13259 - Delta Telesystems Ltd. (Russia). In fact, all of the following ASNs from the above table also have AS13259, Delta Telesystems Ltd. (Russia) as their one and only upstream at the present time: AS39325 - Viptelecom LLC AS41762 - PE Logvinov Vladimir Vladimirovich AS56968 - TemirLan Net Ltd AS34498 - Jilcomservice AS1065 - Extreme Internet On this basis it would appear that the root of the problem in this case lies at AS13259, Delta Telesystems Ltd. (Russia). As a mitigation for these squats, I recommend dropping/blocking all of the IPv4 CIDRs listed above. Additionally, since AS13259 appears to be highly untrustworth at the present time. I would advise blocking all traffic to/from these blocks also: https://bgp.he.net/AS13259#_prefixes 79.173.104.0/21 82.147.68.0/24 82.147.70.0/24 82.147.71.0/24 82.147.75.0/24 85.28.48.0/20 85.89.104.0/21 91.206.16.0/23 193.107.92.0/22 2001:678:68c::/48 Regards, rfg