Windows Trojan Spreads to Android and iOS Devices Via USB

DualToy is a Windows Trojan that has been active since the beginning of 2015, according to SecurityWeek. While it mainly targets Windows PCs, it can also directly affect non-Windows mobile devices that are connected to the infected PC via a USB connection.

The earliest versions of DualToy were only able to infect Android devices, but the malware creators tweaked it to infect iOS devices as well within six months of the Trojan’s release.

So far, DualToy has mainly affected users in China, security firm Palo Alto Networks reported. The firm also said that both individuals and organizations in the U.S., U.K., Thailand, Spain and Ireland had been impacted.

Windows Trojans Opens Up to Android, iOS

When on a PC, DualToy injects processes, modifies browser settings and displays ads, among other behavior. But when a mobile device is connected to the PC via a USB, the Windows Trojan really gets nasty.

DualToy communicates with targeted devices through a USB cable using pairing/authorization records found on the infected PC. The authors assumed that any device connected to the PC USB port would already have been authorized to use the port. That means the pairing records would have already been present and usable for that specific device.

Android devices get hosed because the Trojan copies native code to a connected device and directly executes it. It then activates obtains root privilege, and downloads and installs more Android apps in the background.

iOS devices are treated just as roughly. The Trojan steals information from a connected iOS device easily. That includes IMEI, IMSI, ICCID, serial numbers and, just so they can sell it to annoying telemarketers, your phone number. The Trojan also asks for an Apple ID and password and sends them both to a server without the user’s knowledge.

Securing Endpoints and Networks

Palo Alto Networks recommended that users and organizations deploy both endpoint- and network-based malware prevention solutions. It seems obvious but users must also avoid connecting their mobile phones to any untrusted devices via USB.

The ubiquity of mobile devices presents an attractive target for malware creators. Expect even more types of sophisticated, hardware-based attacks in the future.

Larry Loeb

Principal, PBC Enterprises

Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other...