Ho Mobile, an Italian mobile operator, owned by Vodafone, has confirmed a massive data breach on Monday and is now taking the rare step of offering to replace the SIM cards of all affected customers.
The breach is believed to have impacted roughly 2.5 million customers.
It first came to light last month on December 28 when a security analyst spotted the telco's database being offered for sale on a dark web forum.
While the company initially played down these initial reports, Ho confirmed the incident on Monday, in a message posted on its official website and via SMS messages sent to all impacted customers.
Ho's statement confirms the security researcher's assessment that hackers broke into Ho's servers and stole details on Ho customers, including full names, telephone numbers, social security numbers, email addresses, dates and places of birth, nationality, and home addresses.
While the telco said no financial data or call details were stolen in the intrusion, Ho admitted that hackers got their hands on details related to customers' SIM cards.
Free SIM card replacements
To avoid even the slightest threat of telephone fraud or SIM swapping attacks, the Italian telco is now offering to replace SIM cards for all impacted customers, if they wish, and free of any charges.
"You can go to one of our authorized dealers and request a SIM change free of charge, bringing your current SIM and a valid identity document with you," the company wrote on Monday.
Since the SIM card and customer details have been stolen and could be abused to request a SIM card change, physical presence in the Ho stores will be required, the company said, to avoid allowing hackers to request a SIM change for a legitimate customer via the phone.
The telco said the investigation into the hack is still ongoing, together with local law enforcement agencies.
While security breaches have taken place at various telcos around the world, this is a rare case where the provider does good by its customers and offers free SIM card replacements.