Nansen alerts users to security breach involving vendor

Some Nansen users had their email addresses, password hashes and blockchain addresses exposed in a recent third-party security breach

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Nansen’s Alex Svanevik | Source: Ian Walton for Blockworks

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Blockchain data analytics platform Nansen recently suffered a security incident that exposed some users’ email addresses and passwords.

The breach appears to have originated from a third-party vendor whose system was compromised, allowing an attacker to obtain admin rights to an account used for granting customer access to Nansen.

Nansen CEO Alex Svanevik stated that the company became aware of the attack on Sept. 20. Initial investigations indicate that about 6.8% of its users are affected by the breach.

“These users had their email addresses exposed, a smaller portion also had password hashes exposed, and a last, smallest group also had their blockchain address exposed,” Svanevik said in an X post on Friday.

“We have informed our users via email if and how they’ve been affected,” he added.

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A Nansen spokesperson declined to disclose the name of the vendor, but said it has asked them to communicate on the incident publicly in case others are affected.

Nansen contacted affected users via emails sent from its official [email protected] email address on Sept. 21 between 5 pm and 9 pm UTC, instructing them to reset their passwords.

The team also informed users that while their passwords are not stored in plaintext, malicious attackers could still attempt to gain access to accounts using the compromised password and email address.

Data breaches have become increasingly frequent in the industry of late.

NFT platform OpenSea told users about a data breach in June last year when staff discovered that email addresses had been shared with an external party.

Last month, ConsenSys disclosed that about 7,000 MetaMask users had their private information, including email addresses, compromised between Aug. 2021 and Feb. 2023.

Also in August, embattled crypto companies BlockFi and FTX also reported being indirectly impacted by a cybersecurity breach related to third-party claims administration platform Kroll.


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