The FBI is working with data breach notification service Have I Been Pwned (HIBP) to help notify people and businesses if their accounts were affected by the Emotet botnet, the site reports.
Earlier this year, law enforcement officials around the world conducted an operation to seize control of Emotet's infrastructure. Following the takedown, the FBI contacted HIBP to see whether the service might be an effective means of alerting affected individuals and companies, according to a blog post by HIBP creator Troy Hunt.
As part of this collaboration, the FBI shared more than 4.3 million email addresses, spanning a range of countries and domains, which came from two sources of data the FBI obtained during the takedown. These include email credentials that Emotet stores for sending spam via email service providers and Web credentials from browsers that had stored them to accelerate logins. Given their remediation is similar, both have been categorized as a single breach in HIBP, Hunt says.
The incident has been flagged as "sensitive," meaning it cannot be publicly searched. People will either need to verify they own their address through the notification service or do a domain search to see whether they're affected.
Those who have been affected are advised to change their email account password, as well as passwords and security questions for accounts stored in their inbox or browser. Hunt recommends keeping security software up to date.
Hunt points out this isn't the first time law enforcement has used HIBP. Back in 2018, the Cybercrime Bureau of the Estonian Central Criminal Police used the service to alert people affected by several different breaches.
Read Troy Hunt's full blog post for more details.