Iran is on a hacking spree. The reason why may be ominous.

Charming Kitten and other Iranian cyber operators emerged in the 2010s as the U.S. and Israel initiated their own cyber-attacks on Iran and its nuclear infrastructure. The two countries’ use of a malware virus called Stuxnet, beginning in 2010, is seen as one of the first examples of states using cyber weapons to advance their national security strategies.

Iran, in turn received a huge boost for its cyber operations against the U.S. in 2013 when a former U.S. Air Force sergeant, named Monica Witt, defected to Tehran. The Department of Justice accused her in a 2018 indictment of carrying cyber targeting data to her Iranian handlers.

Since then, the U.S. government and cyber security firms have tied Charming Kitten to a string of strategic hacks, such as on American and Saudi Arabian banks and critical infrastructure, as well as to pure money-making endeavors like ransomware. (This included a 2017 hack of HBO in which the Iranian syndicate threatened to prematurely release Game of Thrones scripts.) The U.S. Treasury Department sanctioned the Charming Kitten network last September, outlining the Iranian tech companies and cyber operators who were supporting the IRGC.

Charming Kitten’s recent campaign against former U.S. officials and academics has largely focused on using fake email accounts and websites to lure in their prey. Proofpoint tracked bogus messages purportedly sent by Professor Karl Roberts of the Royal United Services Institute for Defense and Security Studies — a real person at a genuine organization. The former U.S. officials interviewed by Semafor described getting similar bogus outreach from often real individuals.

The U.S. and Iran have been in conflict since Islamist radicals seized power in Tehran back in 1979, with cyber operations being a middle ground short of actual combat. It just remains to be seen if this can be contained.

Charming Kitten’s cyber operations come as tensions between the Biden administration and Tehran remain high. In March, Iranian-backed militias in Syria killed an American defense contractor operating there. And the U.S. and Iran continue to engage in tit-for-tat seizures of oil tankers operating around the Persian Gulf. Last week, the U.S. Navy said it warded off an attempt by an Iranian warship to capture two oil-carrying vessels near Oman.

Any moves by the IRGC to make good on its threats to assassinate these former U.S. officials would likely breach a U.S. red line. Proofpoint’s reports on the IRGC collecting information on former officials and influential academics through Charming Kitten points in that direction.

Iran has been open about the fact that it’s in a cyber war with the U.S. and that Tehran’s rapidly advancing its capabilities in this battle. Senior Iranian officials have cited the U.S.-Israel Stuxnet attack as the first shot in this digital war.

“The United States started that cyber war, with attacking our nuclear facilities in a very dangerous, irresponsible way that could’ve killed millions of people,” former foreign minister Javad Zarif told NBC News in 2019. “So, there is a cyber war ... and Iran is engaged in that cyber war. But any war that the United States starts, it won’t be able to finish.”

The U.S. has publicly warned about the threat Iran poses to these former U.S. officials and political dissidents on American soil. But there remains uncertainty within the administration about whether the IRGC would actually go through with such targeted assassinations, knowing the potential repercussions.

Iran and its operatives haven’t executed a political hit in the U.S. since the time of the revolution. But their calculations could be shifting. The Booker Prize-winning writer Salman Rushdie, who has been the target of an Iranian death fatwa since 1989, was brutally attacked by a regime supporter last August in New York. And the Department of Justice in January indicted three men for plotting to kill the Iranian political activist Masih Alinejad in the U.S.