In response to feedback from operational security communities, CAIDA's source address validation measurement project (https://spoofer.caida.org) is automatically generating monthly reports of ASes originating prefixes in BGP for systems from which we received packets with a spoofed source address. We are publishing these reports to network and security operations lists in order to ensure this information reaches operational contacts in these ASes. This report summarises tests conducted within usa, can. Inferred improvements during Apr 2023: ASN Name Fixed-By 41378 KirinoNET 2023-04-02 14361 HOPONE-GLOBAL 2023-04-11 Further information for the inferred remediation is available at: https://spoofer.caida.org/remedy.php Source Address Validation issues inferred during Apr 2023: ASN Name First-Spoofed Last-Spoofed 6939 HURRICANE 2016-02-22 2023-04-18 209 CENTURYLINK-US-LEGACY-QWEST 2016-08-16 2023-04-27 6128 CABLE-NET-1 2016-09-03 2023-04-22 20412 CLARITY-TELECOM 2016-09-30 2023-04-29 6181 FUSE-NET 2016-10-10 2023-04-02 25787 ROWE-NETWORKS 2016-10-21 2023-04-27 10796 TWC-10796-MIDWEST 2016-10-24 2023-04-29 271 BCNET 2016-10-24 2023-04-29 1403 EBOX 2016-11-12 2023-04-11 852 ASN852 2017-04-16 2023-04-30 7122 MTS-ASN 2017-05-16 2023-04-30 6461 ZAYO-6461 2017-06-21 2023-04-04 12222 AKAMAI 2018-02-14 2023-04-03 33452 RW 2018-09-19 2023-04-09 398836 2021-03-12 2023-04-24 22773 ASN-CXA-ALL-CCI-22773-RDC 2021-10-24 2023-04-27 26231 SFIA-ASN 2021-10-27 2023-04-29 46997 2021-12-22 2023-04-26 394414 E2WS 2022-05-08 2023-04-25 59 WISC-MADISON 2022-06-14 2023-04-25 397086 GLOBAL-FRAG-NETWORKS-HOUSTON 2022-06-16 2023-04-30 11976 FIDN 2022-11-16 2023-04-25 12183 TALKIE-COMMUNICATIONS 2022-12-10 2023-04-27 399852 2023-02-16 2023-04-27 211380 2023-03-15 2023-04-26 964 GONET-ASN-17 2023-03-15 2023-04-28 41378 KirinoNET 2023-03-23 2023-04-27 23352 SERVERCENTRAL 2023-04-04 2023-04-22 15305 SYRINGANETWORKS 2023-04-05 2023-04-05 14361 HOPONE-GLOBAL 2023-04-11 2023-04-11 395418 ARIN-CHA 2023-04-14 2023-04-16 3701 NERONET 2023-04-18 2023-04-25 855 CANET-ASN-4 2023-04-26 2023-04-29 18615 MAINSTREAM-FIBER 2023-04-30 2023-04-30 Further information for these tests where we received spoofed packets is available at: https://spoofer.caida.org/recent_tests.php?country_include=usa,can&no_block=1 Please send any feedback or suggestions to spoofer-info@caida.org