Handala Hack Group claimed to have wiped about 200,000 U.S. devices in what Chris Krebs, former director of the Cybersecurity and Information Security Agency, called the most consequential wartime cyber attack against the United States ever seen.

"The Iranians are throwing everything they have at this. It is all hands on deck. If their cyber operators are breathing, then they will be on their keyboards," Krebs said.

Since the start of the war in Iran, Handala has emerged as the main online promoter of alleged Iranian cyberattacks.

Iran has invested heavily in efforts to pierce American and Israeli firewalls. Iranian hackers have engaged in cyber operations against Israel for years, with activities aimed at sowing fear, causing chaos, collecting intelligence, and isolating missile targets.

Iran has three different levels of cyber operators whose boundaries are often blurry. The most experienced level is run directly by the Islamic Revolutionary Guard Corps and Iran's Ministry of Intelligence. The most experienced Iranian cyber operators maintain front organizations to provide plausible deniability for attacks and issue public threats.

Iran hires semi-autonomous hacking proxies, cybercriminals, and contractors. Volunteer hacktivists have regularly mobilized behind Tehran, expanding the country's cyber capabilities through a network of affiliated groups.