This isn't an extraordinary claim. Iran is at war, they have a propaganda arm, it would be shocking if they weren't doing this.
What exactly would meet your standard of proof?
Once again, they quote an editor of one of the outlets that ran these stories. The entire article falls apart if the fake journalist is actually a real journalist; this makes it very easy to confirm.
"It was the Iranians, trust us" is not proof. The pretense that it is, is itself deeply offensive.
The United States government is at war with Iran. Sam Altman and Jeff Bezos both have significant interests in pleasing the U.S. government. It would be shocking if they weren't pushing propaganda for the U.S. government.
This isn't news. It's "Iran bad" snarling, badly disguised as journalism.