PowerHammer - Steal data via power lines - Computer not connected to any network can be hacked!

Till now, we have seen various hacks performed through networks (mostly, the internet). But today, I will show you how to hack a computer which isn't connected to any network. Here, you will learn to hack a computer via powerlines. Powerline means the electrical line through which computers get their power - the electricity lines.

Seems, like a magic! But its the reality. Yes, I am late introducing you all to this master piece of hacking as I am busy with many other tasks. But I won't let you down. Articles of The Hacker's Library will always be the best quality articles with complete understanding. So, now let's start with the understanding of this hack.

You need to know a term called air-gapped computer to understand a point in this article. Air-gapping is a security measure that involves isolating a computer or network and preventing it from establishing an external connection. For example, an air gapped computer is one that is physically segregated and incapable of connecting wirelessly or physically with other computers or network devices. In short, air-gapping prevents the computer from being hacked by not connecting it to any network. And here's the trap... Here, you will learn to hack an air-gapped computer.

What happened?

A team of academics has successfully developed and tested malware that can exfiltrate data from air-gapped computers via power lines. The team —from the Ben-Gurion University of the Negev in Israel— named their data exfiltration technique PowerHammer.

PowerHammer works by infecting an air-gapped computer with malware that intentionally alters CPU utilization levels to make the victim's computer consume more or less electrical power.

Sound something like a James Bond movie? Well, the same group of researchers has previously demonstrated various out-of-band communication methods to steal data from a compromised air-gapped computer via light, sound, heat, electromagnetic, magnetic and ultrasonic waves. All these information is available on the net.

How it works?

By default, computers extract power from the local network in a uniform manner. A PowerHammer attack produces a variation of the amount of power a victim's PC sucks from the local electrical network. This phenomena is known as a "conducted emission."

By altering the high and low power consumption levels, PowerHammer malware can encode binary data from a victim's computer into the power consumption pattern. That is, once power hammer gets installed on your computer, it takes control over the processor. To do this, it need administrator privileges (in windows) or root level access (in linux). Once it gets the control, it will follow the following steps:

Step 1 - Read data from disk or memory.

Step 2 - Encode data in binary form and then digital signals containing 0s and 1s.

Step 3 - Send the data in form of current to the power lines. (Conversion from digital signals to analog signals is done automatically by the hardware - the malware just needs to force digital data into processor output lines.)

There are two types of PowerHammer attacks

Well, we have seen how the malware sends data into powerline. But how does the attacker receive this data? To retrieve this data, an attacker must tap a victim's electrical network so it can read the power consumption variation and decode the binary data hidden inside. Based where the attacker places his tapping rig, two types of PowerHammer attacks exists, with two different exfiltration speeds.

The first is "line level power-hammering," and this occurs when the attacker manages to tap the power cable between the air-gapped computer and the electrical socket. The exfiltration speed for a line level hammering is around 1,000 bits/second.

The second is "phase level power-hammering," this version of the attack occurs when the intruder taps the power lines at the phase level, in a building's electrical panel. This version of the PowerHammer attack is more stealthy but can recover data at only 10 bits/second, mainly due to greater amount of "noise" at the power line phase level.

The tapping device isn't anything super-advanced, being a mundane split-core current transformer that can be attached to any electrical line.

This is a non-invasive probe which is clamped around the power line and measures the amount of current passing through it (Fig. 10). The non-invasive probe behaves like an inductor which responds to the magnetic field around a current-carrying cable (Fig. 10 b). The amount of current in the coil is correlated with the amount of current flowing in the conductor. For our experiments we used SparkFun’s split core current transformer ECS1030-L72.

The tapping device (probe) is also capable of sending the recorded data to a nearby computer via WiFi, making data collection easier from afar, without the attacker having to physically connect to the tapping probe.

Scope of this attack

Experiments revealed the attack is successful for stealing data from air-gapped desktops, laptops, servers, and even IoT devices, but the speed exfiltration speed is slower for the latter. Another observation is that exfiltration speed gets better the more cores a CPU possesses.

Mitigations and more details for technically inclined users are available in the research team's paper, entitled "PowerHammer: Exfiltrating Data from Air-Gapped Computers through Power Lines." It also must be said that this malware is only an experiment and if ever deployed in the wild, such a tool would only be found in the arsenal of intelligence agencies and not something that normal users would see every day.

How to prevent yourself from this attack? 

To be true, I didn't knew much about this attack as it includes electrical components and all. Therefore, 50% of above data is just referred from another articles. But, of all the articles I reffered, there wasn't a part like how to prevent this attack. But I know a way to detect this attack and its very simple.

The attack works by sending data through powerlines and hence it has a side effect of increasing the voltage. So, just connect a Voltage Regulator between your computer and the circuit board. Hence, the current flows in the following manner: Computer <-----> Voltage Regulator <-----> Source Power.

If voltage stays high for a long time, you have probably been attacked!!

Where to find more information on this?

As I said above, I don't have much knowledge about it. I haven't implemented it yet and this was just the abstract of it. But what if you want to dive deep into this? This can be done as the authors of PowerHammer have published a research paper online. Thanks to them..

Here's the link of research paper: https://arxiv.org/abs/1804.04014

Thank you for reading this article.. If you got something to learn new, if you liked it, share it with your friends too.