The United States launched an offensive cyber strike against Iranian missile control systems and a spy network on Thursday amid escalating tensions between the two countries, US media reported on Saturday.

US President Donald Trump ordered US Cyber Command to launch the digital strikes, The Washington Post reported.

Read more: Six hack attacks that shook the world

Citing US officials, the newspaper reported that the attack crippled Iranian computers used to control rocket and missile launches.

The cyberattack came as the president held back from conducting airstrikes on Iranian targets in response to the downing of a US Global Hawk drone. Washington said the unmanned drone was in international airspace. Tehran said it was in its airspace. 

Trump claimed he called off the conventional military strike after he learned 150 people would be killed, and said it would not have been "proportionate." Instead, he said Saturday, the US would announce new sanctions on Iran next week. 

A conventional strike could have triggered an Iranian military response and brought the entire Middle East into a major conflict.

Read more: Iran-US tensions flare in the Persian Gulf: What's at stake

Spy group targeted

The Associated Press first reported the cyberattack. Citing two former intelligence officials, it reported that US Cyber Command targeted an Iranian spy group that has tracked the movement of ships passing through the strategic Strait of Hormuz.

The cyber offensive was reportedly in the works for weeks and its launch was proposed following last week's attacks on two oil tankers. US officials blamed Iran for the attacks. Iran denies any involvement. 

Read more: Tanker attacks in the Gulf — evidence or warmongering?

Iran threatens to set region ablaze

Tensions between the two countries have spiked since Washington last year withdrew from the 2015 international nuclear deal and imposed a steady stream of sanctions that have choked off Iranian oil sales and crippled the country's economy.

Iran has shown no signs it will buckle under the Trump administration's "maximum pressure campaign," which analysts say has only hardened Tehran's resolve and strengthened the Islamic Revolutionary Guard Corps.

On Saturday, a senior spokesperson from the Iranian armed forces warned that a US military strike would trigger a crushing response.

"A military mistake from the enemy, particularly from the US and its regional allies, will be tantamount to firing at a powder keg on which are the US and its interests, and it will set the region ablaze and burn up the US, its interests, and its allies," Brigadier General Abolfazl Shekarchi told the semiofficial Tasnim news agency.

US sees spike in hacks from Iran

The cyber strike came as US cybersecurity firms and the Department of Homeland Security said Iran has recently increased its digital attacks against the US government and businesses.

Cybersecurity firms CrowdStrike and FireEye said that suspected Tehran-backed hackers have targeted US government agencies, as well as critical infrastructure, including oil and gas.

The hackers used spear-phishing emails to hack into US systems, although it is unclear if any were successful.

The Department of Homeland Security's agency tasked with infrastructure protection said in a statement Saturday that it was aware of a recent rise in cyber activities against the US government by Iranian regime actors and proxies.

"What might start as an account compromise, where you think you might just lose data, can quickly become a situation where you've lost your whole network," said Cybersecurity and Infrastructure Security Agency Director Christopher Krebs.

The US and Iran have previously engaged in cyber warfare.

In 2010, the US and Israel used the so-called Stuxnet virus to disrupt centrifuges at an Iranian uranium enrichment facility.

Iran showed its capabilities in 2012 when it infected Saudi state-owned oil company Saudi Aramco with a virus that erased data on 30,000 computers.

In 2016, the US indicted seven Iranian hackers for cyberattacks on US banks and a small dam in New York.

cw/aw (AFP, AP)

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