Ezra Harris

Tag: Short Read

  • Spotting Fake Phishing Emails

    Spotting Fake Phishing Emails

    Yesterday I checked my Gmail spam folder, and I saw this email:

    Screenshot of the email header

    The contents of the email are a general threat of a typical phishing email with the following:

    It threatened to lock your various email accounts and asked for $950 sent to a BTC wallet. This is a pretty obvious scam in many ways, including that I have no actual email client setup, just a forwarding address. One interesting thing is that Gmail showed that it came from my email address.

    (in this case, [email protected]). I wanted to see if it’s easy enough to tell how it was spoofed. One way of doing this is viewing the original message, an unprocessed backend version of the email, including the email server logs, when Gmail receives it.

    Using that, you can check whether or not the email was spoofed, aka an email coming from an email address but making it look like it’s from your email. You can find out if it’s spoofed or not usually by checking this line in the original message; you can see mine here:

    Showing that the original IP does not certify the email because it isn’t allowed. I’m pretty sure Gmail checks for that line and sees if it’s a legitimate email, then throws it into spam if it gives a soft fail. And if you grab the IP location, its somewhere in India:

    IP details of email

    In general, you never want to click on any links or follow any instructions given by an email that looks suspicious; make sure you check the message by googling it first; I found many forum posts saying they got the same copy-paste email as I got, just a different email.

    And also, check that it’s not spoofed, as I mentioned before, or a lookalike email, for example:

    From: [email protected]

    faking the email with minor changes, it seems like it’s from [email protected].

    One more thing I found interesting is that in the original message, the email said it was from [email protected] but right after said: “Using Preegsr tmraipj” not sure what that means, and I can’t find any client called that; I’m guessing its a name, but it’s clumsy for someone to leave that in the “from” section.

    Informative posts I found while researching this:

    Explanation of each line on an email message

    How to check if an email is spoofed (in Gmail)

  • Tuning Acceleration on my 3D Printer

    Tuning Acceleration on my 3D Printer

    Yesterday I got my Printrbot Simple Metal plus running, I had gotten it previously running, but it had significant build issues, mainly with no ease of access of the motherboard, when I designed the adapter for the SKR 1.4 motherboard to fit into the old Printrbot motherboard slot, I had no way of accessing the SD card or the USB port without taking it out of the 3D printer. This time, I had a soldering iron, terminal crimps, extra wires, and most importantly, lots and lots of Zip Ties.

    Once built, I could get it up and running with Octoprint on my laptop server. Thanks to Paukstelis for the excellent Octoprint_deploy script, which makes it a breeze to set up multiple Octoprint instances, which shortened hours to only about 5 minutes of setup time.

    Then I PID tuned, which tunes the heater of the Bed and the Hotend, which tests to see how frequently the heater needs to start heating; for example, before a PID tune, the Bed would either heat over the mark with 63°, begin to cool down but then go below the mark by hitting 55°, then heating up too much. Back and forth, thus making an unstable temperature which can affect the print dramatically. By staying stable, you can see an example of before and after with the Octoprint temp graph:

    credit: u/copppypapper on Reddit.com

    Once PID was tuned, I test-printed a ghosting/ringing test cube model, which came back with this:

    test cube 1

    You can see the ringing from the “Y” letter by the bump around. And some lousy plastic trailing on the lines; I then decreased the acceleration, which is how fast it speeds up and slows down, which causes this foul ringing line around corners. And this was the second cube:

    Test Cube 2

    Unfortunately, I still had very similar results from the second cube after turning it down, there is a very slight difference, but the bump is still very much there. But after turning it down even more and slowing the print speeds. I got this result:

    test cube 3

    The third cube was a success. It had eliminated the ringing, with not even a bump before the letter. But at the cost of speed, which I can sacrifice for quality. There are also very inconsistent layer lines which you can see in the images,, which I am working to resolve to get a better, more consistent cube shape.

  • Upgrades for my Ender-3

    I finally got around to fixing and upgrading my Ender-3. I’ve had my Ender3 for almost 2 years now and have occasionally been upgrading when needed. Last year I made my best upgrade to the “silent board” TMC2208 stepper drivers. Which significantly silenced the noise of the printer when printing. As well as a BL touch which helps with bed leveling. (Read more about that process here)

    I hadn’t upgraded it much further than adding an Octoprint device (wireless control software for controlling and printing and a bunch of other features.) But I wanted to spend a bit more time working on the firmware and hardware because of several issues/features. One was a heating issue if I printed twice before it cooled down. Another major one was I needed to modify the firmware for PID Bed tuning (basically calibrating the temperature for my printer to know what the sweet spot is for keeping stable temperatures). I wanted to add “fast probing,” which made the bed leveling process much faster before it started printing, which I learned about thanks to Crosslink’s blog post.

    I moved my printer upstairs and closer to my desk for easy access and quick printing. As well as using an old laptop, I had to lie around for the Octoprint server and the laptop screen as a sort of 3D printer screen monitor. Which displays the webpage, where I can use the touchscreen to control and view information about the printer. Thanks to a nifty program called Ubuntu Frame, Ubuntu Frame uses the screen in “Kiosk mode,” which runs a website in a stripped-down version of chromium at bootup. Thanks to UI customizer, an Octoprint plugin, I could customize the home screen to look sleeker and in Dark mode, which made it easier for the eyes to see and navigate.

    (What’s dark mode? Click the icon below to see)

    I was also able to successfully program Marlin firmware for my printer with the features mentioned earlier. And ran the PID tuning. Another upgrade I wanted to make was to switch to Direct Drive. I had a direct drive setup from another project printer that I wasn’t using, and since in the future I wanted to run flexible plastics that would better run with Direct Drive, I decided I might as well install it at the same time.

    Took a couple of beauty shots with my brother Simeon’s camera while it was printing, and here’s the result:

  • The Benefits of Plastic

    Plastics (or synthetic polymers) were first introduced back in the 19th century when they were trying to find an alternative to Ivory; ivory is also used in billiard balls (or pool balls in the US) Ivory was more commonly made using Elephant tusks, and was used in the making of small sculpted works of art, mini statues and other uses. Such as this Catholic depiction of Mary holding baby Jesus:

    (credit: Wikipedia)

    In 1907 an inventor Leo Baekeland came up with an utterly artificial type of plastic called Bakelite; bakelite’s main attributes were that it was a good insulator of heat and strong. Later, bakelite aided with the production of electronics due to its ease of production and cheapness. Bakelite inspired others to create different types of polymers.

    Today plastic is used in almost every type of profession. It’s used in computers, wires, safety equipment, tubes, ETC.

    Although some say a downside to plastic is its environmental effects, plastic has a lot better attributes than other materials (glass, wood, etc.), like its lightness and strength. And if we were to replace plastic, we could need more resources for the alternatives, which would result in more storage for those substitutes, thus more storage on trucks and space on freight ships, planes, etc.

    Even if the US and Europe decided to stop using plastic entirely, it wouldn’t even stop 1% of ocean pollution. Over time more and more plastics are invented for specific cases, and over time it may get better for the environment.

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