Glossary
SIM swap
Definition
A SIM-swap attack is when someone persuades a mobile carrier to port a victim's number onto a SIM the attacker controls.
Why it matters
The dominant real-world attack against SMS two-factor authentication, and the reason security people dislike SMS OTP. It is a social-engineering attack on carrier support staff, which is why it works against numbers backed by large call centres and rather less well against numbers with no account and no support line to socially engineer.
Related reading
Part of the HushSMS glossary — 18 terms defined.