After Biden Warning, Hackers Define ‘Critical’ as They See Fit

After a furious run of ransomware attacks in the first half of the year, President Joe Biden in July warned his Russian counterpart, Vladimir Putin, that Russia-based hacking groups should steer clear of 16 critical sectors of the U.S. economy.

In recent days, a Russia-linked ransomware group called BlackMatter attacked a grain cooperative in Iowa, an incident that appears to test Biden’s terms since “food and agriculture” is one of the protected sectors.

In messages with Bloomberg News, however, BlackMatter said it has rules for how it operates its ransomware operation, a sort of ethical playbook for an illegal ...