Mobile community operator SK Telecom, which serves roughly 34 million subscribers in South Korea, has confirmed that it suffered a cyber assault earlier this month that noticed malware infiltrate its inside programs, and entry knowledge associated to prospects’ SIM playing cards.
The breach occurred at round 11pm native time, on the night time of Saturday 19 April 2025, in what’s believed to have been an assault deliberately timed to use a day and time when there could also be much less workers monitoring in place.
Responsibly, SK Telecom knowledgeable the Korean Internet & Security Agency (KISA) the next day, and fulfilled its authorized obligation to inform the Personal Information Protection Commission on Monday 21 April that there had been a possible knowledge breach.
Although no buyer names, delivery dates, or monetary particulars had been leaked, the knowledge figuring out SIM playing cards is taken into account extremely delicate – because it might allow a decided legal to hijack victims’ cellphone numbers in a “SIM Swap” assault.
SK Telecom says that its engineers detected and deleted the malware risk on its community, and took the compromised community servers offline as quickly because it realised {that a} knowledge breach could have occurred. Unfortunately, regardless of its greatest efforts – hundreds of thousands of customers’ SIM particulars might have been put in danger, and will now be within the palms of cybercriminals.
Although SK Telecom has not confirmed the full variety of customers whose SIM particulars have been uncovered, it has acknowledged that hundreds of thousands of people may very well be in danger.
The excellent news is that SK Telecom says it has seen no proof that the delicate knowledge has been exploited by cybercriminals. The unhealthy information is that it would not essentially know if it had been exploited or not.
Since its breach, SK Telecom has confronted some criticism for the best way it has communicated information of the cyber assault to its prospects. Although it up to date its web site and cell app with a safety advisory, some customers felt they need to even have proactively acquired an SMS alert informing them of the state of affairs.
Apologising for the breach and responding to complaints about its response to the incident, SK Telecom has apologised and begun to ship out SMS notifications to prospects. In addition, the corporate has mentioned it’s strengthening its safety within the hope of stopping comparable incidents in future, and pledged to have a clear inquiry into what occurred.
Hacks like this are a wake-up name for telecoms corporations worldwide that they have to safe their programs towards the specter of cybercriminals and state-sponsored hackers.
And all companies could be clever to study that hackers may try to strike at anytime, day or night time, not simply throughout weekday enterprise hours.
If a hacker can exploit a window of alternative – resembling late within the night on a weekend – to sneak into your community undetected, they will not have any qualms about doing so.
Businesses which might be dealing with vital or delicate knowledge ought to guarantee their alerting programs and incident response plans work by weekends and holidays simply as simply as every other day of the week.