Speak Up: Ransomware Attack Uses Voice Recognition

[UPDATED 9:50AM ET with new ESET information]

First there was a ransomware attack that spoke to its victims via a voice message, and now there's one in the wild that requires the victim read aloud - via voice recognition - the code to free his or her infected mobile device.

Symantec researchers recently spotted a new variant of the so-called Android.Lockdroid.E mobile ransomware that now employs speech recognition APIs for the victim to input the unlock code rather than type it after paying the ransom. This bizarre yet creative twist to raises more questions than it answers about the attackers' intent, given the obvious inefficiency and potential fallibility of the voice-recognition step.

The attack thus far has been targeting Chinese-speaking victims, and a ransom note written in Mandarin appears on the infected device's window with instructions to contract the attackers via QQ instant messaging to receive payment instructions and the unlock code.

Since the victim's device is locked up with the ransomware, he or she must use a separate device to contact the attackers, which in and of itself could discourage or preclude payment if the victim doesn't obtain another mobile device to finish the transaction.

That bulky and inefficient feature of the attack has researchers baffled. The attackers may well just be "live-testing" this as another payment approach, says Kevin Haley, director of Symantec Security Response.

But Haley says it's likely this new voice recognition feature could backfire on the Lockdroid attackers. "My guess is this isn't going to work as well," he says. "If the victim can't figure out how to pay the ransom, [the campaign] isn't going to do so well," Haley says, adding that the researchers were unable to discern how many victims had fallen for the attack.

Android.Lockdroid.E's new voice-recognition step follows its previous version's similarly odd step of requiring the victim to scan a barcode in order to log into the QQ messaging app: via a separate, second device. Symantec a year ago first detailed the barcode feature, noting that the malware posed as a porn app and gave the attackers admin rights on the infected device.

The newest version harbors a few implementation bugs, according to Symantec, including improper speech recognition intent-firing and copy/paste flaws. The researchers say the authors likely are experimenting with new features to shake down their victims.

Lockdroid.E is similar but not related to another mobile ransomware variant dubbed Android/LockScreen.Jisut by ESET, whose number of detections doubled in 2016 over the previous year, according to new ESET data. Lukas Stefanko, a malware researcher at ESET, says his firm calls LockDroid.E Android/LockerPin or Android/Locker.

Symantec pointed out similarities between the two Android ransomware variants: "The usage of QQ messenger as the communication platform is common across this wave of ransomware, and almost all of the Lockdroid and LockScreen variants that use Mandarin instructions share similar properties," says Dinesh Venkatesan, principal threat analysis engineer at Symantec. "In short, we can say that they may be from similar groups, but we don't have solid proof that the two ransomware variants are related."

An earlier variant of Android/LockScreen.Jisut actually spoke to the victims via a voice message. "After infecting the device, a female voice speaking Chinese 'congratulated' the victim and asked for 40 Yuans (approx. 6 dollars) to unlock it," ESET said in a mobile ransomware report published this month.

That was likely the handiwork of young Chinese attackers—possibly teenagers, according to ESET. Unlike most ransomware that requires payment via Bitcoin or pre-paid cash vouchers to keep the money and recipient hidden, the LockScreen attackers don't seem to be trying to hide. "If the information in the QQ profiles is valid, the malware operators are Chinese youths between 17 and 22 years old," ESET said in its report.

Service With A Fee

Symantec's Haley notes that other ransomware attackers are providing more "customer service" such as instant messaging assistance to help their victims learn about Bitcoin and how to obtain it, for example. "They're just out there trying to get their percentage of [victim] customers up," he says.

Ransomware overall is exploding: new data this week from Check Point found that ransomware attacks doubled around the globe in the second half of 2016, from 5.5% to 10.5% of all attacks. Desktop ransomware families Locky (41%), Cryptowall (27%), and Cerber (23%) are the biggest culprits.

The Hummingbad family of malware rules the mobile ransomware world for now, at 60%, according to Check Point. Meantime, other less pervasive but more bizarre forms of ransomware such as Lockdroid. E are popping up on mobile devices as ransomware authors toy with new ways to shake down their victims.

Lockdroid is going through "an evolution," Symantec's Haley notes.

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