Email verification service takes itself offline after 800 million records get publicly exposed
Researchers find a non-protected MongoDB instance amounting to 150GB of unique data
An online email verification service has taken itself offline after approximately 809 million of its customers' emails were exposed through an unprotected server.
Researchers discovered a non-password protected MongoDB instance amounting to 150GB of data split across four separate collections last week. They analysed this exposed data, 808,593,939 records in total, and published their findings on Thursday.
The exposed records are owned by an email verifications service named Verifications.io, according to the researchers.
The largest drive, named 'mailEmailDatabase', itself contained three folders; Emailrecords (798,171,891 records exposed), emailWithPhone (4,150,600 records exposed) and businessLeads (6,217,358 records exposed).
Beyond names, email addresses and phone numbers, the exposed records may also have contained additional information such as city, phone number, date of birth, and gender.
Cyber security expert Bob Diachenko, who discovered and analysed the exposed data with NightLion Security's Vinny Troya, then cross-referenced these records with the HaveIBeenPwned database.
They established these were unique records that had never been exposed in any previous 'collections'. Included in this bracket, for example, are the monster Collections #1 to #5 leaks of 2.2 billion unique records exposed earlier this year.
Sign up today and you will receive a free copy of our Future Focus 2025 report - the leading guidance on AI, cybersecurity and other IT challenges as per 700+ senior executives
"This is perhaps the biggest and most comprehensive email database I have ever reported," Diachenko wrote in his post.
"Upon verification, I was shocked at the massive number of emails that were publicly accessible for anyone with an internet connection. Some of data was much more detailed than just the email address and included personally identifiable information (PII)."
Clues within the dataset pointed Diachenko to Verifications.io as the likely owner of the non-password protected MongoDB instance.
The company, which offers 'enterprise email validation' as a service, then took its entire website offline the same day he reported the discovery to its support team.
"We appreciate you reaching out and informing us," Verifications.io's support team told Diachenko via email. "We were able to quickly secure the database. Goes to show, even with 12 years of experience you can't let your guard down.
"After closer inspection, it appears that the database used for appends was briefly exposed. This is our company database built with public information, not client data."
This fact has confused the researchers, however, who in their blog post posed the question "why close the database and take the site offline if it indeed was "public"?"
Verifications.io remains offline at the time of publication.

Keumars Afifi-Sabet is a writer and editor that specialises in public sector, cyber security, and cloud computing. He first joined ITPro as a staff writer in April 2018 and eventually became its Features Editor. Although a regular contributor to other tech sites in the past, these days you will find Keumars on LiveScience, where he runs its Technology section.
-
Thousands of Microsoft Teams users are being targeted in a new phishing campaignNews Microsoft Teams users should be on the alert, according to researchers at Check Point
-
Microsoft warns of rising AitM phishing attacks on energy sectorNews The campaign abused SharePoint file sharing services to deliver phishing payloads and altered inbox rules to maintain persistence
-
Warning issued as surge in OAuth device code phishing leads to M365 account takeoversNews Successful attacks enable full M365 account access, opening the door to data theft, lateral movement, and persistent compromise
-
Amazon CSO Stephen Schmidt says the company has rejected more than 1,800 fake North Korean job applicants in 18 months – but one managed to slip through the netNews Analysis from Amazon highlights the growing scale of North Korean-backed "fake IT worker" campaigns
-
Complacent Gen Z and Millennial workers are more likely to be duped by social engineering attacksNews Overconfidence and a lack of security training are putting organizations at risk
-
Hackers are abusing ConnectWise ScreenConnect, againNews A new spear phishing campaign has targeted more than 900 organizations with fake invitations from platforms like Zoom and Microsoft Teams.
-
The Allianz Life data breach just took a huge turn for the worseNews Around 1.1 million Allianz Life customers are believed to have been impacted in a recent data breach, making up the vast majority of the insurer's North American customers.
-
A new, silent social engineering attack is being used by hackers – and your security systems might not notice until it’s too lateNews Security researchers have warned the 'FileFix' technique, which builds on the notorious 'ClickFix' tactic, is being used in the wild by threat actors.

