On September 22, 2023, Nansen posted a letter on its X (formerly known as Twitter) account explaining a recent vendor data breach. In this notice, Nansen explains that the incident resulted in an unauthorized party being able to access consumers’ sensitive information, which includes their email addresses, password hashes and blockchain addresses. Upon completing its investigation, Nansen began sending out data breach notification letters to all individuals whose information was affected by the recent data security incident.

If you receive a data breach notification from Nansen, it is essential you understand what is at risk and what you can do about it. A data breach lawyer can help you learn more about how to protect yourself from becoming a victim of fraud or identity theft, as well as discuss your legal options following the Nansen vendor data breach. For more information, please see our recent piece on the topic here.

What Caused the Data Breach Affecting Nansen Users?

The data breach affecting Nansen users was only recently announced, and more information is expected in the near future. However, Nansen’s recent X post provides some information about what happened. According to this source, on September 20, 2023, a reputable vendor that Nansen uses to perform certain services informed the company that their systems had been compromised. Evidently, the incident allowed the hacker to access admin rights to an account used to provision customer access to Nansen’s platform.

In response, Nansen quickly terminated the unauthorized party’s access and then proceeded with an investigation.

The Nansen investigation is still ongoing; however, at this point, the company estimates that 6.8 percent of its user base was affected.

After learning that sensitive consumer data was accessible to an unauthorized party, Nansen reviewed the compromised files to determine what information was leaked and which consumers were impacted. While the breached information varies depending on the individual, it may include your email address, password hash and blockchain address.

Nansen’s X post, dated September 22, 2023, indicated that Nansen sent emails explaining the data breach letters to anyone who was affected. These emails should provide victims with a list of which information of theirs was compromised.

More Information About Nansen

Nansen is a blockchain analytics platform headquartered in Hong Kong. Nansen analyzes 100M+ labeled wallets and their activity on Ethereum, Polygon, Avalanche, and numerous other L1 and L2 blockchains. Nansen employs more than 100 people and generates approximately $52 million in annual revenue.