Security Archives - Igor Oseledko

To Mask or Not to Mask

Igor — Tue, 31 Mar 2026 02:10:54 +0000

Originally published March 31, 2020 @ 3:17 pmEffectiveness of face masks against the coronavirus has been debated to death in both popular and scientific literature. Here are the two most common mistakes made by journalists and by people who should know better. Asking the Wrong Question “Can Face Masks Prevent Coronavirus?” or “Can wearing a […]

The post To Mask or Not to Mask appeared first on Igor Oseledko.

Checking Linux Account Password

Igor — Wed, 25 Mar 2026 03:57:45 +0000

Originally published March 25, 2020 @ 4:48 pmOn occasion you may need to check if an account has a specific password. For example, when you build VMs, you may use some default passwords for some default accounts (i.e. root) that should be changed later by your password management application. Except that the password management application […]

The post Checking Linux Account Password appeared first on Igor Oseledko.

The Coronavirus Discussion

Igor — Wed, 04 Mar 2026 21:06:25 +0000

Originally published March 5, 2020 @ 12:42 pmJust a few words about the coronavirus. Clearly, the Internet is in need of my contribution to this topic. You might’ve noticed this: whenever there is a discussion about the coronavirus, some dolt appears out of nowhere and says something along the lines of “to put things in […]

The post The Coronavirus Discussion appeared first on Igor Oseledko.

Updating Lynis

Igor — Sat, 28 Feb 2026 02:22:08 +0000

Originally published February 29, 2020 @ 5:04 pmLynis is an excellent security audit tool for Linux and various Unix derivatives. I have a small wrapper script that runs Lynis via a cron job, does a selective diff with the previous run’s output, and sends me an email. Unfortunately, Lynis does not update itself automatically and […]

The post Updating Lynis appeared first on Igor Oseledko.

Hiding Passwords

Igor — Thu, 19 Feb 2026 21:16:29 +0000

Originally published February 21, 2020 @ 9:02 amI’ve touched on this subject previously, but suddenly felt I should repeat myself. The big issue with using passwords from command line is shell history. Regardless of how careful you are, eventually you’ll enter a password in clear text in your terminal session. It will then end up […]

The post Hiding Passwords appeared first on Igor Oseledko.

Home-Brew Ransomware Defense

Igor — Fri, 26 Dec 2025 08:18:31 +0000

Originally published December 28, 2019 @ 12:42 amThe first well-known case of ransomware was documented in 1989. The so-called AIDS Trojan was delivered on a floppy disc; encrypted data; demanded $189.00 (nearly four hundred bucks in today’s money) as a “license fee.” The trojan was quickly defused due to its reliance on weak symmetric cryptography. […]

The post Home-Brew Ransomware Defense appeared first on Igor Oseledko.

Basic Data Recovery in Linux

Igor — Fri, 31 Oct 2025 16:02:05 +0000

Originally published November 1, 2022 @ 8:22 amHave you noticed how the letters “e” and “r” are neighbors on your keyboard? And an unrelated question: do you know the difference between crontab -e and crontab -r commands? Look it up if you don’t. Honestly, I’ve never used the crontab -r command in my many years […]

The post Basic Data Recovery in Linux appeared first on Igor Oseledko.

Dealing with GitHub Desktop

Igor — Mon, 13 Oct 2025 17:41:17 +0000

Originally published October 14, 2022 @ 10:12 amGitHub Desktop is one of those terrible applications that I still have to use occasionally, much to my regret. I can’t tell you if a five-year-old or a cat coded it, but this application with relatively straightforward functionality has more bugs than Florida. Sometime in the spring of […]

The post Dealing with GitHub Desktop appeared first on Igor Oseledko.

Bulk-Adding IPTables Rules

Igor — Thu, 02 Oct 2025 22:45:05 +0000

Originally published October 4, 2019 @ 11:58 amI’ve been using my mod of this handy script to block countries with iptables. One issue with the script is that it is adding rules one-by-one using the iptables -A syntax. This is the proper way to add rules, but it does take a long while. And here’s […]

The post Bulk-Adding IPTables Rules appeared first on Igor Oseledko.

Late Night Rant: Trump, Bolton, Iran, Saudis

Igor — Fri, 19 Sep 2025 07:14:17 +0000

Originally published September 20, 2019 @ 10:11 pmUsually I try to keep politics out of my blog, but this time I just can’t resist. A few days after Trump fires Bolton for being too tough on Iran (among other reasons), the supposedly Iranian-backed somebodies launched a daring and devastating attack, crippling Saudi Arabia’s oil production. […]

The post Late Night Rant: Trump, Bolton, Iran, Saudis appeared first on Igor Oseledko.