Iran-linked hackers have broken into the personal email inbox of Kash Patel, FBI’s director, publishing photographs of him and other documents on the internet, the hackers and the bureau said on Friday.

On their website, the hacker group Handala Hack Team said Patel “will now find his name among the list of successfully hacked victims”. The hackers published a series of personal photographs of Patel sniffing and smoking cigars, riding in an antique convertible and making a face while taking a picture of himself in the mirror with a large bottle of rum.

The FBI confirmed Patel’s emails had been targeted. In a statement, FBI spokesperson Ben Williamson said: “We have taken all necessary steps to mitigate potential risks associated with this activity,” and that the data involved was “historical in nature and involves no government information”.

Handala, which presents itself as a group of pro-Palestinian vigilante hackers, is considered by western researchers to be one of several personas used by Iranian government cyberintelligence units. Handala recently claimed the hack of Michigan-based medical devices and services provider Stryker on 11 March, saying they had deleted a big trove of company data.

Handala did not return messages. Reuters could not access its website late on Friday.

Alongside the photographs of Patel, the hackers published a sample of more than 300 emails, which appear to show a mix of personal and work correspondence dating between 2010 and 2019.

Reuters was not able to independently authenticate the Patel messages, but the personal Gmail address that Handala claims to have broken into matches the address linked to Patel in previous data breaches preserved by the dark web intelligence firm District 4 Labs. Alphabet-owned Google, which runs Gmail, did not respond to a request for comment.

Iran-linked hackers – who initially kept a low profile after the US and Israel launched coordinated strikes against the Islamic Republic last month – have increasingly boasted of their cyber operations as the conflict drags on.

In addition to the hack against Stryker, Handala on Thursday claimed to have published the personal data of dozens of employees at the defense company Lockheed Martin stationed in the Middle East. In a statement, Lockheed Martin said it was aware of the reports and had policies and procedures in place “to mitigate cyber threats to our business”.

Gil Messing, chief of staff at Israeli cybersecurity company Check Point, said the hack-and-leak operation against Patel was part of Iran’s strategy to embarrass US officials and “make them feel vulnerable”.

The Iranians, he said, are “firing whatever they have”. It is not unusual for foreign hackers to target senior officials’ personal emails, and breaches and leaks happen periodically. Hackers famously broke into the personal Gmail account of John Podesta, Hillary Clinton’s campaign chair, ahead of the 2016 election and published much of the data on WikiLeaks.

In 2015, teenage hackers broke into then-CIA director John Brennan’s personal AOL account and leaked data about US intelligence officials. Relatively unsophisticated breaches of this nature are in line with a US intelligence assessment reviewed by Reuters on 2 March. The assessment said Iran and its proxies could respond to the killing of Iranian Supreme Leader Ayatollah Ali Khamenei with low-level hacks against US digital networks.

Iran-linked hackers may have other emails in reserve. Last year, another group operating under the pseudonym “Robert” told Reuters it was considering disclosing 100 gigabytes of data stolen from Susie Wiles, the White House’s chief of staff, and other figures close to Donald Trump.

Reuters has not been able to verify the claim and the group has not responded to messages in several months.