Schedule

Schedule

Sunday, February 1

1422817200 The Tech Guy
1422828000 This Week in Tech

Monday, February 2

1422900000 Tech News Today
1422903600 Triangulation
1422909000 iPad Today
1422921600 Tech News 2Night

Tuesday, February 3

1422986400 Tech News Today
1422990000 MacBreak Weekly
1422997200 Security Now
1423004400 Before You Buy
1423008000 Tech News 2Night
1423011600 All About Android
1423020600 Padre's Corner

Wednesday, February 4

1423067400 FLOSS Weekly
1423072800 Tech News Today
1423076400 Windows Weekly
1423083600 This Week in Google
1423094400 Tech News 2Night
1423096200 Android App Arena
1423101600 Ham Nation

Thursday, February 5

1423159200 Tech News Today
1423162800 Know How...
1423166400 Marketing Mavericks
1423171800 Coding 101
1423175400 Home Theater Geeks
1423180800 Tech News 2Night
1423182600 The Giz Wiz

Friday, February 6

1423245600 Tech News Today
1423249200 This Week in Law
1423267200 Tech News 2Night

Saturday, February 7

1423335600 The Tech Guy

Sunday, February 8

1423422000 The Tech Guy
1423436400 This Week in Tech

Monday, February 9

1423504800 Tech News Today
1423508400 Triangulation
1423513800 iPad Today
1423526400 Tech News 2Night

Tuesday, February 10

1423591200 Tech News Today
1423594800 MacBreak Weekly
1423602000 Security Now
1423609200 Before You Buy
1423612800 Tech News 2Night

Most Recent Episodes

The Tech Guy
The Tech Guy 1157 January 31st, 2015

Is there a way to make internet browsing safe for the kids at home?

Tech News 2Night

AOL makes cuts, Google makes profits, and China builds a greater firewall.

This Week in Law

Can you pirate your own video game?

Tech News Today
Episode #1186: Cyanogen MS? January 30th, 2015

Google and Amazon report financials

This Week in Computer Hardware

NVIDIA and the GTX 970, PCPer VLAN, and Direct X 12 in Windows 10.

The Giz Wiz
Episode #1503: RIP SkyMall January 29th, 2015

Remembering SkyMall.

Tech News 2Night

Social media announcements, Cortana predicts the Super Bowl

Know How...

Back from Daytona, G+ Feedback, and Networking.

Home Theater Geeks

Ultra High Def, the future of TV, and the alliance.

Coding 101

The philosophy of assembly.

Know How... 106

Bad USB, I Am Groot, and Defcon

August 14 2014

A USB hack that will make you drop your packets, Patrick Djelahanty shows how he built the "Baby Groot" out of common parts, see soundwaves, lock picking, and Defcon wrap up.

"Bad USB"
* German Researchers Karsten Knoll and Jacob Lell discovered an exploit in the way USB works
* ALL USB devices use some form of controller. They're small computers that interface the USB serial communications protocol with whatever device we want to connect via USB.
-- That controller is actually a small computer... and the computer runs an operating system that is determined by firmware.

What's the Exploit?
* The way that USB was created, that firmware is updateable. It's updateable because the creators of the USB standard wanted manufacturers to be able to reprogram the firmware if a flaw was ever discovered in that firmware.
* HOWEVER, that also means that a malicious user (hacker) could reprogram the firmware to make the device act in a way that the manufacturers had not intended.

What does that all mean?
* This means that a USB flash drive could be reprogramed to act like a keyboard
-- So after you plug it in, it issues a series of keystrokes that (for example) open Internet Explorer, navigate to a page that contains malware, then close the browser... all in a matter of seconds
* Or a USB flash drive could be reprogrammed to act like a network adapter
-- All the traffic you send and receive from your network would pass through this new network adapter, which would forward the packet stream to another computer before sending your trafic to the proper destinations.

Worse still... since your computer has USB devices INTEGRATED into the system (Keyboard, Mouse, Webcamera, Card Reader) a compromised USB device could be used to compromise the USB devices in your computer, which would then compromise any USB device that connects to your computer.

Ok... so why not just run an anti-virus? Or copy over new firmware? Or just make USB firmware non-programmable?

Let's take that one at a time: Anti-Virus
* Your system cannot see past the controller of a USB device.
-- The way USB devices work, the system can query the controller, and the controller will tell the system the status of the USB device.
-- If the controller is compromised, then you cannot trust it to report the correct status
** In other words, the only way an Anti-Virus would work would be if the malware infecting the USB device was programmed to tell the system that it was compromising the controller... an unlikely scenario.

Copying New Firmware:
* As with the Anti-Virus question, the system cannot see past the controller.
* When you update firmware on a USB device, the new firmware is loaded into memory, then the controller is responsible for overwriting its old firmware and reporting back to the system with the new firmware status.
* If I was writing BadUSB malware, the first thing I would to would be to disable that process: Allow the controller to copy the new firmware to memory, then strip off the revision number of the new firmware and report THAT to the system.
-- The system thinks it has new firmware, but the malware is still there.

Making USB devices unprogrammable:
* This is the most likely solution, but there are two MAJOR problems
1. It doesn't fix the BILLIONS of USB devices that are already in the wild.
2. If a manufacturer ever discovers a problem with their firmware (say, an exploit) there is no way to patch it.

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