Simjacking occurs when an attacker calls a mobile operator and impersonates a target in order to trick the operator into porting the target’s phone number to the attacker’s device. The attacker can then exploit anything the number grants them access to, and can bypass SMS-based two-factor authentication. In Monroe’s case, the attacker was able to trick the operator into switching the phone number by providing Monroe’s birth date, which is available on Wikipedia.
It’s worth noting that Monroe did have precautions in place. She stressed that she is “absurdly paranoid about security,” and says she uses two-factor authentication on everything, along with unique, complex passwords. Simjacking can bypass these safeguards however, since it doesn’t target the victim directly and takes advantage of a human employee at a mobile phone company.
As technical defenses improve, social engineering attacks will increase. Even if your organization has the most advanced defenses in place, your security posture is still severely lacking if one of your employees can be tricked into giving the attacker what they want. New-school security awareness training can ensure that your employees have the skills to resist these attacks. The BBC has the story: https://www.bbc.com/news/technology-50043230