A blog post by the company said RF protocols were often used to control simple operations of industrial machines, like switching on a motor, lifting a load or manoeuvring a heavy vehicle.
The Trend Micro team said it had been able to perform attacks from within or from outside the RF range. Remote attackers from outside the RF range could either carry out a computer-borne attack — or take control of a computer used to either program or control the RF device — or obtain temporary access to the facility where the device was located and leave behind an embedded device for remote access.
The device that the researchers built, known as RFQuack, was used as a tool for studying the attacks that could be carried out.
"When powered up, the device stays idle to save power. When set to receiving mode, it goes into deep-sleep mode and wakes up only when a valid radio packet is received," the researchers said.
"When a valid packet is received, its default behaviour is to resend it immediately enough times to make the target receiver 'obey' the command.
"In fact, before retransmission, RFQuack has modified the packet on the fly, according to a configurable set of rules. Alternatively, RFQuack can be used to collect radio packets or just send manually crafted packets."
Controllers could be attacked and used to control construction cranes. industrial cranes and mobile hoists in production settings, the team said.
Such industrial devices tended to be used for a long time in production; given that support times would expire, it would be impossible to obtain patches as new products would have replaced the old ones.
Trend Micro suggested the following measures to minimise the risk of this type of attacks:
- Inspecting technical manuals before purchasing a device (most of the manuals are available even online) and ensuring that some form of configurable pairing is available;
- Periodically changing the fixed (ID) code, if possible;
- Keeping the programming computer off the network or hardening its security as if it were a critical endpoint;
- Preferring remote control systems that offer dual-technology devices, such as those with virtual fencing; and
- Choosing devices that use open, well-known, and standard protocols such as Bluetooth Low Energy.
Businesses were advised to ensure secure protocols and processes by:
- Implementing rolling-code mechanisms (or better) and providing firmware upgrades to devices;
- Building on open, well-known, and standard protocols like Bluetooth Low Energy (which some vendors are already doing);
- Considering future evolutions when designing next-generation systems; and
- Using tamper-proof mechanisms to hinder reverse engineering (most of the products that we’ve analysed are easily accessible).