Apple emerged as a guardian of user privacy this year after fighting FBI demands to help crack into San Bernardino shooter Syed Rizwan Farook’s iPhone. The company has gone to great lengths to secure customer data in recent years, by implementing better encryption for all phones and refusing to undermine that encryption.
But private information still escapes from Apple products under some circumstances. The latest involves the company’s online syncing service iCloud.
Russian digital forensics firm Elcomsoft has found that Apple’s mobile devices automatically send a user’s call history to the company’s servers if iCloud is enabled — but the data gets uploaded in many instances without user choice or notification.
“You only need to have iCloud itself enabled” for the data to be sent, said Vladimir Katalov, CEO of Elcomsoft.
The logs surreptitiously uploaded to Apple contain a list of all calls made and received on an iOS device, complete with phone numbers, dates and times, and duration. They also include missed and bypassed calls. Elcomsoft said Apple retains the data in a user’s iCloud account for up to four months, providing a boon to law enforcement who may not be able to obtain the data either from the user’s carrier, who may retain the data for only a short period, or from the user’s device, if it’s encrypted with an unbreakable passcode.
“Absolutely this is an advantage [for law enforcement],” Robert Osgood, a former FBI supervisory agent who now directs a graduate program in computer forensics at George Mason University, said of Apple’s call-history uploads. “Four months is a long time [to retain call logs]. It’s generally 30 or 60 days for telecom providers, because they don’t want to keep more [records] than they absolutely have to. So if Apple is holding data for four months, that could be a very interesting data repository and they may have data that the telecom provider might not.”
It’s not just regular call logs that get sent to Apple’s servers. FaceTime, which is used to make audio and video calls on iOS devices, also syncs call history to iCloud automatically, according to Elcomsoft. The company believes syncing of both regular calls and FaceTime call logs goes back to at least iOS 8.2, which Apple released in March 2015.
And beginning with Apple’s latest operating system, iOS 10, incoming missed calls that are made through third-party VoIP applications like Skype, WhatsApp, and Viber, and that use Apple CallKit to make the calls, also get logged to the cloud, Katalov said.
Because Apple possesses the keys to unlock iCloud accounts, U.S. law enforcement agencies can obtain direct access to the logs with a court order. But they still need a tool to extract and parse it.
Elcomsoft said it’s releasing an update to its Phone Breaker software tool today, that can be used to extract the call histories from iCloud accounts, using the accountholder’s credentials. Elcomsoft’s forensic tools are used by law enforcement, corporate security departments, and even consumers. The company also leases some of its extraction code to Cellebrite, the Israeli firm the FBI regularly uses to get into seized phones and iCloud data.
In some cases Elcomsoft’s tool can help customers access the iCloud even without account credentials, if they can obtain an authentication token for the account from the accountholder’s computer, allowing them to get iCloud data without Apple’s help. The use of authentication tokens also bypasses two-factor authentication if the accountholder has set this up to prevent a hacker from getting into their account, Elcomsoft notes on its web site.
Apple’s collection of call logs potentially puts sensitive information at the disposal of people other than law enforcement and other Elcomsoft customers. Anyone else who might be able to obtain the user’s iCloud credentials, like hackers, could potentially get at it too. In 2014, more than 100 celebrities fell victim to a phishing attack that allowed a hacker to obtain their iCloud credentials and steal nude photos of them from their iCloud accounts. The perpetrator reportedly used Elcomsoft’s software to harvest the celebrity photos once the accounts were unlocked.
Generally, if someone were to attempt to download data in an iCloud account, the system would email a notification to the account owner. But Katalov said no notification occurs when someone downloads synced call logs from iCloud.