Featured Articles

WordPress Profiling with XHProf (Debugging & Optimizing Speed)
Hardening Guide for phpList
Continuous Documentation: Hosting Read the Docs on GitHub Pages (2/2)
Trusted Boot (Anti-Evil-Maid, Heads, and PureBoot)
Introducing BusKill: A Kill Cord for your Laptop
Crowdfunding on Crowd Supply (Review of my experience)
WordPress Multisite on the Darknet (Mercator .onion alias)
Detecting (Malicious) Unicode in GitHub PRs
Nightmare on Lemmy Street (A Fediverse GDPR Horror Story)
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Introducing BusKill: A Kill Cord for your Laptop

Bus Kill: A USB Kill Cord for your Laptop

This post will introduce a simple udev rule and ~$20 in USB hardware that effectively implements a kill cord Dead Man Switch to trigger your machine to self-destruct in the event that you're kicked out of the helm position.

Rubber Ducky I <3 you; you make hack time lots of fun!

Let's consider a scenario: You're at a public location (let's say a cafe) while necessarily authenticated into some super important service (let's say online banking). But what if--after you've carefully authenticated--someone snatch-and-runs with your laptop?

Maybe you can call your bank to freeze your accounts before they've done significant financial harm. Maybe you can't.

Or maybe your laptop was connected to your work VPN. In less than 60 seconds and with the help of a rubber ducky, the thief could literally cause millions of dollars in damages to your organization.

Surely there must be some solution to trigger your computer to lock, shutdown, or self-destruct when it's physically separated from you! There is: I call it BusKill.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Introducing BusKill: A Kill Cord for your Laptop

Mitigating Poisoned PGP Certificates (CVE-2019-13050)

Cert Flooding Featured Image

This article will describe PGP Certificate Flooding attacks as well as inform the reader

How to detect if you have a poisoned certificate in your keyring, How to identify & clean the poisoned cert, and How to update the configuration to prevent it from importing poisoned certs in the future

Last month, an attacker spammed several high-profile PGP certificates with tens of thousands (or hundreds of thousands) of signatures (CVE-2019-13050) and uploaded these signatures to the SKS keyservers.

Without looking very deep, I quickly stumbled on 4 keys that were attacked last month:

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Mitigating Poisoned PGP Certificates (CVE-2019-13050)

Ephemeral Firefox as a Site-Specific Browser (3/3)

Site-Specific Ephemeral Firefox featured image showing a firewall between the facebook and firefox icons

This article is a part 3/3 of a series describing how to setup an Ephemeral Firefox session as a Site-Specific Browser. The ultimate goal is to be able to have a self-destructing browsing session that can only access a single company's services, such as Google or Facebook.

Part 1/3: Ephemeral Firefox in Ubuntu Part 2/3: Ephemeral Firefox with Extensions Part 3/3: Ephemeral Firefox as a Site-Specific Browser

After setting up the Site-Specific Ephemeral Firefox Browser, you can then blacklist services designated to your Site-Specific browser(s) (such as Google or Facebook) from your main browser. This significantly improves your ability to browse the internet without your activity being tracked by these companies -- leaving your sensitive data vulnerable to being stolen by hackers.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Ephemeral Firefox as a Site-Specific Browser (3/3)

Ephemeral Firefox with Extensions (2/3)

icon of ephemeral firefox with icons of popular extensions below it

I recently posted about how to create a sandboxed firefox profile to compartmentalize (and shred) your firefox browsing history in an Ephemeral Firefox session. But so far I've only covered how to create a simple vanilla firefox profile. What if you want your Ephemeral Firefox to include a few basic extensions?

This post will cover how to add extensions to your Ephemeral Firefox profile.

Part 1/3: Ephemeral Firefox in Ubuntu Part 2/3: Ephemeral Firefox with Extensions Part 3/3: Ephemeral Firefox as a Site-Specific Browser Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Ephemeral Firefox with Extensions (2/3)

Ephemeral Firefox in Ubuntu (1/3)

ephemeral firefox

This post will describe how to create an Ephemeral Firefox session. The ultimate goal of an Ephemeral Firefox session is to unlink your browsing sessions day-to-day and reduce tracking via fingerprinting.

Part 1/3: Ephemeral Firefox in Ubuntu Part 2/3: Ephemeral Firefox with Extensions Part 3/3: Ephemeral Firefox as a Site-Specific Browser

This technique can also be used to compartmentalize your internet activity by using the Ephemeral Firefox session as a Site Specific Browser. This can be especially useful for websites that are infamous for tracking users across the internet and selling the data they collect. For example, you can blacklist all facebook domains in your main browser and only use Ephemeral Firefox sessions that have been whitelisted exclusively for facebook domains--effectively compartmentalizing your facebook activity from the rest of your internet activity.

Another great use-case for an Ephemeral Firefox is for public access computers such as those at libraries, hotels, and printing shops.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Ephemeral Firefox in Ubuntu (1/3)

How to check Whonix version in Qubes

Whonix 14 just came out last month. I went to update, but I couldn't figure out what version I was currently running. The documentation said to run this command, but the output didn't make sense when I ran it on my whonix-gw TemplateVM.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: How to check Whonix version in Qubes

fix phplist 500 error due to random_compat

So you've just done a fresh install of phplist, but when you attempt to load it in your browser, you get a 500 Internal Server Error. But the error log is empty! It's possible that phplist is suppressing the errors produced by the included library random_compat. This blog post will describe this possible issue, and how to resolve it.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: fix phplist 500 error due to random_compat

Detect outgoing port blocking with nmap and portquiz.net

This post will describe how to detect if your network is blocking outgoing ports. In this test, we'll be using nmap and the fine website portquiz.net

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Detect outgoing port blocking with nmap and portquiz.net

Detecting Censorship or ISP Network Tampering with OONI

This article will introduce a tool to detect censorship or network tampering using the Open Observatory of Network Interference (OONI) android app, which is part of the Tor Project.

The OONI project's mission is to collect data on network providers to determine where the Internet is free and where it's being manipulated. For example, the OONI Explorer displays a world map of such data.

On the OONI explorer, you can drill-down on the world map into a specific country to get a list of websites that were detected as being blocked from within that country.

For example, when I looked at the history of OONI probe runs within the US, I saw a list of the usual suspects: gambling sites, pornography sites, torrenting sites, etc. More surprising (at least to me) was the number of pastebin sites that were banned. And, despicably, there was a network in the US blocking The Internet Archive

When I looked at the data from scans within another great "free country" = India, I saw a lot of cherry-picked censorship on facebook and news articles as it relates to the 2017 genocide of Rohingya Refugees in Burma and various muslim/hindu conflicts.

Anyone
. . . → Read More: Detecting Censorship or ISP Network Tampering with OONI