"Industry was extremely fast to respond to this," Nohl said during his talk on Wednesday. "[They] took away the incentives for criminals to even research this vulnerability by putting in the fix even before we got to demonstrate it."
During the two-year research process, more than 1,000 SIM cards were experimented on by Nohl and his team. The findings revealed a major vulnerability in SIM cards that would allow an attacker to download malicious software onto the victim's SIM card, access data and operate it as the normal owner would.
According to Nohl, the process would start when a miscreant sends a text message to the victim's SIM card that they don't even see because it's sent in binary format. While the message attempts to communicate with the SIM card, there are security protocols in place that causes the card to flag the message. The SIM then responds to the attacker's message and within that message is data that can be decrypted due to the antiquated Data Encryption Standard (DES) technology used by mobile carriers, Nohl said.Included in the data is a cryptographic signature key that would allow the attacker to upload small applications – known as applets – to the device, giving them complete control of it, Nohl said.
While some mobile carriers brushed off the vulnerability, leading him to believe they didn't look into the issue, Nohl said that a majority of the industry has been extremely constructive working with his team as well as with one another."[That] made this a real success story in mitigation," he said. "It is a new research field that generated the first, not the last, results of its kind."