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11 Examples of Data Breaches Caused By Misdirected Emails

  • 17 March 2021

Tessian’s mission is to secure the human layer by empowering people to do their best work, without security getting in their way.

While phishing, ransomware, and brute force attacks tend to make headlines, misdirected emails (emails sent to the wrong person) are actually a much bigger problem.

In fact, in organizations with 1,000 employees, at least 800 emails are sent to the wrong person every year. That’s two a day. You can find more insights in The Psychology of Human Error and The State of Data Loss Prevention 2020

Are you surprised? Most people are. That’s why we’ve rounded up this list of 11 real-world (recent) examples of data breaches caused by misdirected emails. And, if you skip down to the bottom, you’ll see how you can prevent misdirected emails (and breaches!) in your organization

If you’re looking for a bit more background, check out these two articles:

  1. What is a Misdirected Email?
  2. Consequences of Sending an Email to the Wrong Person

11 examples of data breaches caused by misdirected emails 

1. University support service mass emails sensitive student information

University and college wellbeing services deal with sensitive personal information, including details of the health, beliefs, and disabilities of students and their families. 

Most privacy laws impose stricter obligations on organizations handling such sensitive personal information—and there are harsher penalties for losing control of such data.

So imagine how awful the Wellbeing Adviser at the University of Liverpool must have felt when they emailed an entire school’s worth of undergraduates with details about a student’s recent wellbeing appointment.

The email revealed that the student had visited the Adviser earlier that day, that he had been experiencing ongoing personal difficulties, and that the Adviser had advised the student to attend therapy.

A follow-up email urged all the recipients to delete the message “immediately” and appeared to blame the student for providing the wrong email address.

One recipient of the email reportedly said: “How much harder are people going to find it actually going to get help when something so personal could wind up in the inbox of a few hundred people?”

2. Trump White House emails Ukraine ‘talking points’ to Democrats

Remember in 2019, when then-President Donald Trump faced accusations of pressuring Ukraine into investigating corruption allegations against now-President Joe Biden?

Once this story hit the press, the White House wrote an email—intended for Trump’s political allies—setting out some “talking points” to be used when answering questions about the incident (including blaming the “Deep State media”).

Unfortunately for the White House, they sent the email directly to political opponents in the Democratic Party.

White House staff then attempted to “recall” the email. If you’ve ever tried recalling an email, you’ll notice that it doesn’t normally work. 

Recalling an email only works if the recipient is on the same exchange server as you—and only if they haven’t read the email. Looking for information on this? Check out this article: You Sent an Email to the Wrong Person. Now What?

Unsurprisingly, this was not the case for the Democrats who received the White House email, who subsequently leaked it on Twitter. 

3. Australia’s Department of Foreign Affairs and Trade  leaked 1,000 citizens’ email addresses

On September 30, 2020, Australia’s Department of Foreign Affairs and Trade (DFAT) announced that the personal details of over 1,000 citizens were exposed after an employee failed to use BCC. So, who were the citizens Australians who have been stuck in other countries since inbound flights have been limited (even rationed) since the outbreak of COVID-19.

The plan was to increase entry quotas and start an emergency loans scheme for those in dire need. Those who had their email addresses exposed were among the potential recipients of the loan.

Immediately after the email was sent, employees at DFAT tried to recall the email, and event requested that recipients delete the email from their IT system and “refrain from any further forwarding of the email to protect the privacy of the individuals concerned.”

4. Serco exposes contact traces’ data in email error 

In May 2020, an employee at Serco, a business services and outsourcing company, accidentally cc’d instead of bcc’ing almost 300 email addresses. Harmless, right? Unfortunately not. 

The email addresses – which are considered personal data – belonged to newly recruited COVID-19 contact tracers. While a Serco spokesperson has apologized and announced that they would review and update their processes, the incident nonetheless has put confidentiality at risk and could leave the firm under investigation with the ICO. 

5. Sonos accidentally exposes the email addresses of hundreds of customers in email blunder 

In January 2020, 450+ email addresses were exposed after they were (similar to the example above) cc’d rather than bcc’d. 

Here’s what happened: A Sonos employee was replying to customers’ complaints. Instead of putting all the email in BCC, they were CC’d, meaning that every customer who received the email could see the personal email addresses of everyone else on the list. 

The incident was reported to the ICO and is subject to potential fines.

“Remember: email addresses are considered personally identifiable information (PII) and are therefore protected under compliance standards like the GDPR. ”

6. Gender identity clinic leaks patient email addresses

In September 2019, a gender identity clinic in London exposed the details of close to 2,000 people on its email list after an employee cc’d recipients instead of bcc’ing them.

Two separate emails were sent, with about 900 people cc’d on each. 

While email addresses on their own are considered personal information, it’s important to bear in mind the nature of the clinic. As one patient pointed out, “It could out someone, especially as this place treats people who are transgender.” 

The incident was reported to the ICO who is currently assessing the information provided. But, a similar incident may offer a glimpse of what’s to come. 

In 2016, the email addresses of 800 patients who attended HIV clinics were leaked because they were – again – cc’d instead of bcc’d. An NHS Trust was £180,000. Bear in mind, this fine was issued before the introduction of GDPR.

7. University mistakenly emails 430 acceptance letters, blames “human error”

In January 2019, The University of South Florida St. Petersburg sent nearly 700 acceptance emails to applicants. The problem? Only 250 of those students had actually been accepted. The other 400+ hadn’t.

While this isn’t considered a breach (because no personal data was exposed) it does go to show that fat fingering an email can have a number of consequences. 

In this case, the university’s reputation was damaged, hundreds of students were left confused and disappointed, and the employees responsible for the mistake likely suffered red-faced embarrassment on top of other, more formal ramifications. The investigation and remediation of the incident also will have taken up plenty of time and resources. 

8. Union watchdog accidentally leaked secret emails from confidential whistleblower

In January 2019, an official at Australia’s Registered Organisations Commission (ROC) accidentally leaked confidential information, including the identity of a whistleblower. How? The employee entered an incorrect character when sending an email. It was then forwarded to someone with the same last name – but different first initial –  as the intended recipient. 

The next day, the ROC notified the whistleblower whose identity was compromised and disclosed the mistake to the Office of the Australian Information commissions as a potential privacy breach.

9. Major Health System Accidentally Shares Patient Information Due to Third-Party Software for the Second Time This Year

In May 2018 Dignity Health – a major health system headquartered in San Francisco that operates 39 hospitals and 400 care centers around the west coast – reported a breach that affected 55,947 patients to the U.S. Department of Health and Human Services. 

So, how did it happen? Dignity says the problem originated from a sorting error in an email list that had been formatted by one of its vendors. The error resulted in Dignity sending emails to the wrong patients, with the wrong names. Because Dignity is a health system, these emails also often contained the patient’s doctor’s name.

That means PII and Protect health information (PHI) was exposed. 

10. Inquiry reveals the identity of child sexual abuse victims

This 2017 email blunder earned an organization a £200,000 ($278,552) fine from the ICO. The penalty would have been even higher if the GDPR has been in force at the time. When you look at the detail of this incident, it’s easy to see why the ICO wanted to impose a more severe fine.

The Independent Inquiry into Child Sexual Abuse (IICSA) sent a Bcc email to 90 recipients, all of whom were involved in a public hearing about child abuse. 

Sending a Bcc means none of the recipients can see each other’s details/ But the sender then sent a follow-up email to correct an error—using the “To” field by mistake.

The organization made things even worse by sending three follow-up emails asking recipients to delete the original message—one of which generated 39 subsequent “Reply all” emails in response.

The error revealed the email addresses of all 90 recipients and 54 people’s full names. 

But is simply revealing someone’s name that big of a deal? Actually, a person’s name can be very sensitive data—depending on the context. In this case, IICSA’s error revealed that each of these 54 people might have been victims of child sexual abuse.

11. Boris Johnson’s dad’s email blunder nearly causes diplomatic incident

Many of us know what it’s like to be embarrassed by our dad. 

Remember when he interrogated your first love interest? Or that moment your friends overheard him singing in the shower. Or when he accidentally emailed confidential information about the Chinese ambassador to the BBC.

OK, maybe not that last one. That happened to the father of U.K. Prime Minister Boris Johnson in February 2020.

Johnson’s dad, Stanley Johnson, was emailing British officials following a meeting with Chinese ambassador Liu Xiaoming. He wrote that Liu was “concerned” about a lack of contact from the Prime Minister to the Chinese state regarding the coronavirus outbreak.

The Prime Minister’s dad inexplicably copied the BBC into his email, providing some lucky journalists with a free scoop about the state of U.K.-China relations.

It appears the incident didn’t cause any big diplomatic issues—but we can imagine how much worse it could have been if Johnson had revealed more sensitive details of the meeting.

“Before we adopted Tessian's technology, we didn't believe we had any problems with misaddressed emails. After a pilot, we realized that was only because these issues weren't being reported.”
Andrew Cheung Partner and General Counsel at Dentons

Prevent misdirected emails (and breaches) with Tessian Guardian

Regardless of your region or industry, protecting customer, client, and company information is essential. But, to err is human. So how do you prevent misdirected emails?

With machine learning

Tessian turns an organization’s email data into its best defense against human error on email. Our Human Layer Security technology understands human behavior and relationships and automatically detects and prevents emails from being sent to the wrong person.

Yep, this includes typos, accidental “reply alls” and cc’ing instead of bcc’ing. Tessian Guardian can also detect when you’ve attached the wrong file.

Interested in learning more about how Tessian can help prevent accidental data loss and data exfiltration in your organization? You can read some of our customer stories here or book a demo.

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