01/03/2020
if an attacker or a piece of mobile malware can get into the kernel of iOS or Android, then it can do anything it wants, including presenting fake authenticator-app screens.
"One of my clients had an iPhone 4 and was using Microsoft Authenticator," Turner said, indicating another authenticator app. "All an attacker would need to do is to get an iPhone 4 exploit. My client was traveling in a high-risk country, his phone was cloned and then after he left the country, all sorts of interesting things happened to his accounts."
Some Android phones are safer than iPhones
And don't think iOS devices are safer than Android ones -- they're not. There are just as many known exploits for either one, and Weidman extracted the encryption keys from an older iPhone in a matter of seconds onstage.
The iPhone's Secure Enclave offers "some additional security, but the authenticator apps aren't using those elements," said Weidman. "iOS is still good, but Android's [security-enhanced] SELinux is the bane of my existence as someone who's building exploits."
"We charge three times as much for an Android pentest than we charge for an iOS one," Turner said, referring to an exercise in which hackers are paid by a company to try to pe*****te the company's security. "Fully patched Android is more difficult to go after."
In short, "we need to move away from usernames and passwords," Turner said.
Biometric authentication such as fingerprint readers and facial recognition, Weidman said that it's "better than nothing when used in addition to passwords."
Turner wasn't so sure.
"I am fundamentally opposed to using biometrics because it's non-revocable," he said, citing a famous case from Malaysia in which a man's index finger was cut off by a gang to steal the man's fingerprint-protected Mercedes. "Fingerprint readers are biometric toys."
The only form of two-factor authentication without security problems right now, Turner said, is a hardware security key such as a Yubikey or Google Titan key.
"I've got two Yubikeys on me right now," Turner said. "Hardware separation is your friend."
Apps like Google Authenticator are only as safe as the devices they run on