SK Telecom Offers SIM Replacements After Major Data Breach

South Korean telecom network SK Telecom is providing free SIM card replacements to all 25 million mobile subscribers following an April 19 security breach where malware compromised Universal Subscriber Identity Module data.

Despite the company's announcement, only 6 million replacement cards will be available through May 2025. The stolen data potentially includes IMSI numbers, authentication keys, and network usage information, though customer names, identification details, and financial information remain secure. The primary risk is unauthorized SIM swapping attacks, where threat actors could clone SIM cards.

How would you do that?

[fuzzyfuzzyfungus]

My, admittedly layman's, understanding was that SIMs used asymmetric key cryptography for authentication purposes; rather than a shared secret or the like, with the private key never leaving the UICC during authentication(or even on request, the user is considered a potential threat for cloning purposes).

I can imagine a variety of weak customer service 'authentication' scenarios where having the sort of data that they obtained would probably be useful to an attacker; there's probably a call center scrip

Why physical?

[Virtucon]

Why not eSim? I mean, most phones produced over the past 5 years have the capability.

Re:

[ctilsie242]

Because e-SIMs are a step back. You have to be an old fogie to remember in the US when, on CDMA networks, you had to beg the provider to accept your phone, and one provider just refused to have any phone on its network that they didn't sell. Another sort of allowed stuff, but you had to jump through a crapload of hoops.

Then came SIM cards. Didn't matter who made your phone. If it was unlocked, it worked. Going to another country? Pop in a foreign SIM, or maybe two. Swap them out when needed, freely.

e

Re:

[tlhIngan]

Because e-SIMs are a step back. You have to be an old fogie to remember in the US when, on CDMA networks, you had to beg the provider to accept your phone, and one provider just refused to have any phone on its network that they didn't sell. Another sort of allowed stuff, but you had to jump through a crapload of hoops.

Then came SIM cards. Didn't matter who made your phone. If it was unlocked, it worked. Going to another country? Pop in a foreign SIM, or maybe two. Swap them out when needed, freely.

e-SIMs a