The DOJ has indicted three former Verizon and AT&T employees for alleged membership in a crime-ring known as the "The Community"; the indictment says the telco employees helped their confederates undertake "port-out" scams (AKA "SIM-swapping" AKA "SIM hijacking"), which allowed criminals to gain control over targets' phone numbers, thereby receiving SMS-based two-factor authentication codes.
Once in possession of these codes, attackers could take control of targets online accounts, including their banking and cryptocurrency exchange accounts (and also web-based email accounts that could serve as a gateway to many other systems). The returns could be massive, and several cryptocurrency users suffered losses in the millions.
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