I lost my voice before speaking at DEFCON... and went on anyways - Cobalt Strike Research and Development
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I lost my voice before speaking at DEFCON… and went on anyways

Thanks to my open source work, I have a lot of opportunities to speak. In 2011, I gave 30 talks between conferences, professional groups, and invitations to private organizations. This week, much of my industry has collectively gone on vacation to Las Vegas for BlackHat USA, BSides Las Vegas, and of course… DEFCON.

I was fortunate to have an opportunity to speak or demonstrate my work at all three events. Wednesday I spoke at the BlackHat arsenal. This event involves standing at a pod in the hallway and speaking over the noise of the conference for one hour. It’s one of my favorite events because it’s focused on demonstrations and I get a chance to interact with everyone in the audience.


Thursday was a mad rush. I spent the morning at the BSides conference. I gave my talk, hung around to answer questions, hopped a cab, and found myself back at Caesar’s Palace to demonstrate Armitage again at BlackHat.

For me, the big show was DEFCON though. This is where I would release the results of my 7-month DARPA effort, Cortana. And, despite the many times I’ve had the opportunity to share my work, something happened that I have never experienced before a talk: I lost my voice.

Thursday night, while I practiced my talk, my voice stopped working. It went to a very harsh whisper and my throat felt sore. I decided to stop practicing and focus on testing my live demonstrations instead.

I woke up at 7:30am Friday morning and I couldn’t speak.


My talk was at noon. I first paid the $6/bottle minibar fee and drank every bottle of water I could find in my room.  I then tried putting a hot towel on my neck.

No voice.

I walked to the Walgreens Pharmacy. I used my phone and pointing to communicate with the pharmacist. She wasn’t too enthusiastic. She told me to take some ibuprofen and suck on cough drops.

As I checked out, I used gestures to communicate with the cashier. She switched to American Sign Language to communicate with me. I don’t know American Sign Language beyond hello. I smiled and left.

At this point, it’s time to head to the Rio. I’m at a loss for options. I thought about emailing the lead speaker liaison and asking to switch my time or give my spot back to an alternate. I couldn’t get behind that option mentally. I had no idea what I would do at this point, but I knew I would make the show go on.

Downstairs, I’m waiting in line for a taxi cab. I exchange several glances with the guy behind me. Finally, he asks if I’m headed to the same place and asks if I want to share a cab. I gesture yes. Thankfully… I was saved the trouble of finding a way to communicate with the driver.

Once we were in the car, I pulled out my laptop and wrote a message explaining my strange behavior at the moment.

I justified continuing to “speak” despite having no voice. I figured at the very least… I had live demonstrations and possibly, I could croak out parts of my talk by keeping the microphone really close.

We get to the hotel and pay the cab. I go to the speaker registration area. I think there is something truly ironic about registering at the speaker registration area with no voice. Again, I used my laptop to communicate with the DEFCON staff.

At this time, it’s 11:15am. I’m on at noon. I have no voice beyond a very harsh sounding whisper that I dare not use for fear of losing even that.

I go to the speaker ready room. The staff manning the room does the usual, “can I help you?” I pull out my laptop and communicate through a text editor. They laugh and send me to the next room to sit with the other speakers. Several folks from the EFF were discussing their Q&A panel that would happen at the same time. The room also had buzz as General Alexander was in our same suite. The tight security kept us planted at our table.

I used the text-to-speech feature on my Macintosh to converse with my fellow speakers. It was funny to type a thought, press enter, and watch for reactions. After a few rounds of this, I felt like I was participating somewhat in the conversation.

I converted my presentation to PDF. I knew, at worse, I could maybe try using the text to speech feature to communicate some things verbally. Having a PDF would allow me to keep my slides up and a terminal for typing text at the same time. I still had no idea what I would do, but a plan was forming.

My DEFCON speaker goon, Bushy, introduced himself and I explained my situation in a text editor. The speaker goon’s role is to make get speaker’s where they’re going, help them watch the clock, and make sure everything goes smooth. I attempted to speak, close to Bushy’s ear, to test my voice and indicate that I still had something left. Sadly… I didn’t. My voice was still a terribly hoarse whisper.

We then started the trek to the Penn and Teller theater where I would deliver my presentation.

Bushy asked if I tried hot tea with honey yet. I had tried a few things, but not the hot tea. I signed that I had not. We went to Starbucks where there was an incredibly long line. Bushy jumps right to the front and states “I’ll pay for all of your drinks if you just order a hot tea”. He immediately followed it up with “I have a speaker here who is on in 10 minutes and he lost his voice”. The nice couple at the front of the line immediately put the order in and they refused anyone’s offer to compensate them for the tea.

I added three packets of honey to the tea and drank such a big initial swig that I… burnt my tongue. Desperate times call for desperate measures?

We then proceed to the Penn and Teller theater. As we walk, hotel security keeps stopping me and explaining that I can’t carry a drink. Each time, I had to look back and get Bushy’s attention to intervene on my behalf. I didn’t have the voice to explain myself after all.

The final guard, right before the theater, shook his head and laughed when he learned about the situation.

We then enter the Penn and Teller theater. This theater has two levels and seats about 1,500 people. I don’t know if it was configured differently for DEFCON. This part’s a blur to me. I do know that I approached a real stage, saw the sophisticated lighting gear around me, and as I looked at the tiered seating to my left and right… the theater was nearly full.

I’ve never spoken at DEFCON before and I did not know what to expect. I didn’t expect I would see such a full room or find myself escorted to such a prominent stage. I felt like a musician who was expected to perform… but couldn’t.

I see friends in the audience who try to greet me. From stage, I point to my voice and make a motion with my hands to indicate that I had no voice. They got the message and I could see the “Oh… my…” look in their face.

I wasn’t nervous at this point but I still had no idea what would happen.

I setup my laptop and opened a text editor. I wrote:

“Life is an adventure. Here I am speaking to ~1,000 of you. We’re going to have fun today, but you should know… I lost my voice”

Some people noticed it and I could immediately here the “haha, oh my” reaction.

I kept drinking my tea and honey.

Bushy introduces me and states that this is the first time in DEFCON history a speaker has… not had their voice.

By this time, I knew I could croak some things. At worse, I could let everyone read my slides and make a short comment about each. This would still get the content across.

I brought the microphone close and found I could croak enough to speak. My tempo was slow at first. As I kept going (and drinking my tea) my voice slowly came back. It never came back all the way, but it was 100x better than I expected.

Defcon 2012
I was able to deliver the entire 50 minute lecture as I intended to. My demonstrations worked. And I had a great experience.

Thank you Bushy for saving the day for me. You went above and beyond as a speaker goon and while I had no idea what I would do, I thank you for helping me get up to the stage where everything worked out.

This is one speaking experience that I will never forget.