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 Jul 2024: ASN Name Fixed-By 4922 SHENTEL 2024-07-26 Further information for the inferred remediation is available at: https://spoofer.caida.org/remedy.php Source Address Validation issues inferred during Jul 2024: ASN Name First-Spoofed Last-Spoofed 40676 AS40676 2016-08-29 2024-07-31 27364 ACS-INTERNET 2016-09-27 2024-07-30 20412 CLARITY-TELECOM 2016-09-30 2024-07-01 2152 CSUNET-NW 2017-11-08 2024-07-31 21804 ACCESS-SK 2019-06-09 2024-07-28 46997 2021-12-22 2024-07-13 12183 TALKIE-COMMUNICATIONS 2022-12-10 2024-07-27 3701 NERONET 2023-04-18 2024-07-26 855 CANET-ASN-4 2023-04-26 2024-07-18 400282 2023-04-27 2024-07-26 202400 2023-05-08 2024-07-28 61461 Airtek Solutions C.A. 2023-05-13 2024-07-31 394660 CHOICETEL-ER 2023-10-07 2024-07-05 394684 WISPERNET 2024-01-17 2024-07-25 55 UPENN 2024-02-26 2024-07-17 394195 CLEARNETWORX 2024-03-22 2024-07-29 20326 TERASWITCH 2024-04-15 2024-07-09 214961 2024-05-14 2024-07-25 393530 TLU 2024-05-22 2024-07-27 19935 CRRS 2024-05-29 2024-07-23 25853 ELJY30540 2024-06-11 2024-07-29 216211 2024-06-22 2024-07-27 13371 DUKE-INTERCHANGE 2024-07-03 2024-07-31 17049 MBO-NET 2024-07-13 2024-07-13 395337 MACST-VEGAS 2024-07-14 2024-07-14 150325 2024-07-18 2024-07-18 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