The incidents were disclosed on October 4 and reveal the risks organizations face when attackers gain access to legitimate employee accounts. Nikkei has not attributed either incident to a specific hacking group or confirmed whether the two attacks were connected.
The more recent incident involved an employee's Microsoft 365 account. According to Nikkei, attackers gained unauthorized access to the account and used it on September 30 to send approximately 9,000 emails.
The messages were sent to people both inside and outside the company. Some recipients were journalistic sources and other individuals who had previously communicated with Nikkei employees.
The emails contained links leading to malicious websites. Because the messages were sent from a legitimate Nikkei employee account, recipients could have been more likely to trust them. This type of account compromise can allow attackers to use an organization's existing relationships to distribute phishing messages.
Nikkei said the incident may have exposed recipients' names and email addresses, along with the contents of some emails. The company is still investigating the number of people whose personal information may have been affected. According to Nikkei, “There may be an increase in emails impersonating Nikkei employees or our group companies,”
Nikkei also disclosed a separate incident involving an employee's Google Workspace account. The account was accessed without authorization beginning in late July.
The company discovered the intrusion in early August after receiving an alert from Google. Nikkei then changed the account's password and said it has not detected any further unauthorized access.
The incident may have exposed information belonging to 1,646 employees and business partners. The potentially affected information included names and email addresses.
Nikkei said the exposed information did not include data related to its readers or journalistic sources. The company also said it has found no evidence that the information was misused.
After the Microsoft 365 incident, Nikkei changed the affected password and contacted recipients of the phishing emails, asking them to delete the messages. The company warned that additional emails impersonating Nikkei employees or its group companies could appear.
Nikkei has also reported the incidents to Japan's data protection authority. Investigations into the scope of the Microsoft 365 compromise and the information potentially exposed are continuing.
Nikkei has experienced other cybersecurity incidents in recent years. In November 2025, the company disclosed a malware-related credential theft incident that potentially exposed information connected to more than 17,000 employees and business partners.
The recent news has notably increased the number of consumers potentially exposed in the incident. “We're deeply saddened to share the news that the recent data breach affects more customers than originally thought,” Trezor said on X.
As per Trezor, the additional 67000 customers placed orders from November 2019 to August 2021.
The leaked data consists of customers' email, phone numbers, names, addresses, order numbers, and shipping addresses. According to Trezor, the data was stored by ShipMonk even though Trezor had earlier received assurance that previous consumer data had been erased.
“Throughout our entire relationship with ShipMonk, we repeatedly requested and received written assurance confirming the deletion of the data, in line with our contract, data policy, and past communications. We are very disappointed that, despite receiving this confirmation, the data was not deleted in their systems,” Trezor said.
According to experts, the breach is not impacting Trezor’s own systems.
Trezor said its hardware wallets are safe and there are no signs that customers’ recovery seed phrases or private keys were breached in the leak.
As per Trezor, “All affected customers have been emailed directly. If you didn’t receive an email, then you are not affected.”
But Trezor and cybersecurity experts are worried that the stolen data could be exploited for social engineering and targeted phishing attacks. Threat actors could misuse customers’ details regarding their Trezor purchases to create scam phone calls or fraud messages.
This can be a serious problem for cryptocurrency users. A threat actor could mimic a company employee if they know someone owns a Trezor wallet and ask the target to verify their wallet or account.
If successful, the attacker could steal the target’s recovery seed phrase, which can allow access to cryptocurrency funds. “Trezor systems were not compromised, and your device is secure. But please be alert for fake emails, phone calls, fraudulent letters, and potential risks to physical security,” the company added.
The announcement comes after the August incident when 13,689 customers had been impacted by the same shipping-provider. At the time, Trezor estimated around 14,000 customers to have been affected by the breach. The recent disclosure of 67,000 suggests the scope of the incident was larger than expected.