U.S. financial regulators are warning industry firms to step up their defences against possible cyberattacks emanating from Iran.

New York’s Department of Financial Services (DFS) issued an alert calling on firms to bolster their cybersecurity precautions due to a rising risk of cyberattacks from hackers affiliated with the Iranian government.

The warning cited Iran’s pledge to retaliate for the assassination of Qassem Soleimani by the U.S. government as the reason for heightened concern.

“Given Iranian capabilities and history, U.S. entities should prepare for the possibility of cyberattacks,” the alert said, noting that “Iran has a history of launching cyberattacks against the U.S., and the financial services industry.”

In particular, the DFS said that Iranian hackers reportedly carried out denial of service attacks against several major U.S. banks in 2012 and 2013. In June 2019, the U.S. government reported a rise in “highly destructive attacks that delete or encrypt data” with ties to Iran.

As a result, the agency said that it “strongly recommends” that all firms “heighten their vigilance against cyberattacks.”

“Iranian-sponsored hackers have historically relied primarily on common hacking tactics such as email phishing, credential stuffing, password spraying, and targeting unpatched devices,” the DFS said.

Among other things, the agency called on firms to ensure that all vulnerabilities are patched; that employees are prepared to deal with phishing attacks; and that multi-factor authentication is fully implemented.

“It is particularly important to make sure that any alerts or incidents are responded to promptly even outside of regular business hours – Iranian hackers are known to prefer attacking over the weekends and at night precisely because they know that weekday staff may not be available to respond immediately,” the DFS said.