T-Mobile has notified a few hundred customers who were targeted by cybercriminals attempting to transfer their phone numbers to new SIM cards. In early October, Motherboard reported that a security researcher discovered a flaw within T-Mobile’s website that allowed hackers unauthorized access to customers’ data, such as email addresses, billing account numbers, and phones’ International Mobile Subscriber Identity (IMSI) numbers. According to a T-Mobile spokesperson, no financial information, passwords, or Social Security numbers were compromised as a result of this targeted attack. The NJCCIC recommends T-Mobile customers change their online account passwords to this and any other sites that share login credentials, set-up a SIM lock, and create a phone password or passphrase that is required when you call T-Mobile support.