A group of four Iranians is accused of hacking US defense firms and organizations.

Four Iranian men were charged by US authorities on Tuesday for their extensive cyber effort, which targeted US federal institutions and sensitive information owned by US defense firms.

The US State and Treasury departments, along with over a dozen US corporations, including Pentagon contractors handling secret material, were among the targets of the hackers, according to an indictment unsealed in the Southern District of New York by prosecutors.

Between 2016 and 2021, "more than 200,000 victim devices, many of which contained sensitive or classified defense information" were compromised by the hacking operation, according to US Attorney General for the Southern District of New York, Damian Williams, who announced initial charges in February.

Whether the State or Treasury departments' networks were effectively breached during the campaign was not immediately apparent. 

One of the main causes of friction in the US-Iran relationship has long been hacking. In 2022, Boston Children's Hospital was the target of a "despicable" cyberattack that FBI Director Christopher Wray attributed to hackers supported by the Iranian government. Tehran refuted any involvement.

Hossein Harooni, Reza Kazemifar, Alireza Shafie Nasab, and Komeil Baradaran Salmani were charged with wire and computer fraud, among other offenses, in the indictment that was revealed on Tuesday. An earlier indictment that was unsealed in the Southern District of New York in February contained charges against Nasab.

The Justice Department reports that the males, who are all in their 30s, are still at large.Three of the individuals were charged by prosecutors with being employed by a fictitious Iranian corporation that offered cybersecurity services.

The four men were hit with sanctions on Tuesday, according to the Treasury Department, which also claimed that they had ties to Iran's military unit, the Islamic Revolutionary Guard Corps. A reward of up to $10 million was also advertised by the State Department in hopes of obtaining information that would help identify or locate the guys.the Permanent Office of Iran at the United Nations.

"Iranian-based criminal activity represents a severe danger to the United States' economic and national security," Attorney General Merrick Garland declared in a statement announcing the frsh accusations.