River Runner: drop a raindrop anywhere in the USA, watch where it ends up

 https://river-runner.samlearner.com/

Teardown of a PC power supply

 https://www.righto.com/2021/05/teardown-of-pc-power-supply.html

You might wonder how the controller chip on the primary side receives feedback about the voltage levels on the secondary side, since there is no electrical connection between the two sides. (In the photo above, you can see the wide gap separating the two sides.) The trick is a clever chip called the opto-isolator. Internally, one side of the chip contains an infra-red LED. The other side of the chip contains a light-sensitive photo-transistor. The feedback signal on the secondary side is sent into the LED, and the signal is detected by the photo-transistor on the primary side. Thus, the opto-isolator provides a bridge between the secondary side and the primary side, communicating by light instead of electricity.

Try This One Weird Trick Russian Hackers Hate

 https://krebsonsecurity.com/2021/05/try-this-one-weird-trick-russian-hackers-hate/

DarkSide and other Russian-language affiliate moneymaking programs have long barred their criminal associates from installing malicious software on computers in a host of Eastern European countries, including Ukraine and Russia. This prohibition dates back to the earliest days of organized cybercrime, and it is intended to minimize scrutiny and interference from local authorities.

In Russia, for example, authorities there generally will not initiate a cybercrime investigation against one of their own unless a company or individual within the country’s borders files an official complaint as a victim. Ensuring that no affiliates can produce victims in their own countries is the easiest way for these criminals to stay off the radar of domestic law enforcement agencies.

 

DarkSide, like a great many other malware strains, has a hard-coded do-not-install list of countries which are the principal members of the Commonwealth of Independent States (CIS) — former Soviet satellites that all currently have favorable relations with the Kremlin, including Azerbaijan, Belarus, Georgia, Romania, Turkmenistan, Ukraine and Uzbekistan. The full exclusion list in DarkSide (published by Cybereason) is below:

Simply put, countless malware strains will check for the presence of one of these languages on the system, and if they’re detected the malware will exit and fail to install.