​The National Portrait Gallery was targeted by 347,602 emails containing spam, phishing and malware attacks in the last quarter of 2019, a freedom of information (FOI) request has revealed.

Over half of the emails, 194,620, were identified as being directory harvest attacks (DHA), a technique used to harvest valid email addresses belonging to employees and associates of the gallery, according to data collected by think tank Parliament Street.

The gallery also blocked 61,710 emails from senders flagged as belonging to a “threat intelligence blacklist”. A further 85,793 emails were intercepted as they were believed to have contained spam content – which is anything from unsolicited marketing to serious phishing and malware. According to the figures, 418 of the emails contained a virus of some kind.

“These figures paint a worrying picture of the volume of malicious email attacks designed to trick unsuspecting staffers into handing over confidential data such as passwords and log-in credentials,” said Andy Heather, VP of security firm Centrify.

“The National Portrait Gallery is an incredibly popular destination for tourists, attracting millions of visitors and members every year, which unfortunately makes it a top target for hackers and cyber criminals seeking to use legitimate, often stolen, credentials to gain access fear of detection.”

Stolen employee credentials are a global problem for all businesses. Last year, figures from Google’s Password Checkup report suggested that 1.5% of all sign-in attempts were being made using details compromised during a data breach.

“Addressing this threat means ensuring a zero-trust approach to employee communication, ensuring suspicious emails are spotted and full checks are made so that managers can be sure all staffers are who they say they are,” Heather added.

In 2017, London art dealers were defrauded out of hundreds of thousands of pounds after hackers successfully breached company email accounts to monitor correspondence between clients. The incident resulted in fresh cyber security guidance being issued by the Society of London Art Dealers, as well as tips for avoiding email fraud.