Data Breaches

Nikkei Says 17,000 Impacted by Data Breach Stemming From Slack Account Hack

The Japanese media giant says compromised Slack credentials were used to steal employee and business partner information.

Wired data leak

Japanese media giant Nikkei on Tuesday reported that hackers had gained access to employee Slack accounts, stealing information pertaining to thousands of individuals.

Nikkei, which is best known for major financial publications such as The Nikkei and Financial Times, said the incident involved malware stealing Slack credentials from an employee’s personal computer. 

The credentials were then used to access employee Slack accounts, which enabled the attacker to steal information pertaining to employees and business partners. 

An investigation showed that names, email addresses and chat histories belonging to over 17,000 of Nikkei’s Slack users were compromised.

“No leakage of information related to sources or reporting activities has been confirmed,” the company clarified.

The hack was discovered in September and passwords have been changed as part of the company’s incident response procedures. 

Advertisement. Scroll to continue reading.

Nikkei noted that while the type of compromised information did not require it to disclose the data breach to authorities, it decided to voluntarily report the incident to Japan’s Personal Information Protection Commission.

Infostealer malware has been known to collect Slack credentials from infected devices. Hudson Rock, which closely monitors infostealer activity, reports that this type of malware has compromised more than 270,000 Slack credentials. The company has identified the infostealer instance that was likely reponsible for the theft of Nikkei Slack credentials.

This is not the only data breach disclosed by Nikkei in recent years. In 2022, the company was targeted in a ransomware attack that impacted customer information.

Related: 10 Million Impacted by Conduent Data Breach

Related: Open VSX Downplays Impact From GlassWorm Campaign

Related: Cybercriminals Trade 183 Million Stolen Credentials on Telegram, Dark Forums

Related Content

Data Breaches

Hackers stole personal, medical, and health insurance information from a company’s data center.

Data Breaches

Hackers stole personal information, medical records, and financial information from the organization’s server.

Data Breaches

An extortion group stole personal, financial, and medical information from the hospital’s network.

Data Breaches

The bank holding company was hacked in June, but the investigation into the incident continues.

Data Breaches

The physical security firm says its alarm monitoring and system functionality have not been affected.

Data Breaches

In March 2026, hackers stole personal, financial, and medical information from the company’s AWS environment.

Data Breaches

Hackers were detected on Analog Devices systems in June, and an investigation found that they stole files.

Data Breaches

Ernst & Young previously confirmed that personal and financial information was stolen from a third-party management platform.

Copyright © 2026 SecurityWeek ®, a Wired Business Media Publication. All Rights Reserved.

Exit mobile version