Odido Data Breach 2026: 6.2 Million Accounts Exposed in Netherlands' Largest Hack

In what cybersecurity experts are calling one of the largest data breaches in Dutch history, telecom provider Odido has suffered a massive cyberattack exposing sensitive information from 6.2 million customer accounts. The February 2026 breach represents a catastrophic security failure affecting nearly the entire customer base of the Netherlands' largest mobile provider, with stolen data including highly sensitive personal information that experts warn is 'gold worth for criminals.'

What is the Odido Data Breach?

The Odido data breach occurred on February 7-8, 2026, when hackers infiltrated the company's customer contact system and downloaded sensitive personal information from approximately 6.2 million accounts. Interestingly, the hackers themselves alerted Odido to the breach, claiming to have stolen millions of records. The company, formerly known as T-Mobile Netherlands before rebranding to Odido in 2023, serves approximately 6.9 million customers, meaning nearly 90% of its user base was potentially affected.

What Data Was Stolen?

According to Odido's investigation and cybersecurity experts, the stolen data includes:

• Full names and addresses
• Mobile phone numbers and email addresses
• Customer numbers and birthdates
• IBAN bank account numbers
• Passport or driver's license numbers and validity dates

What Was NOT Stolen:

• Passwords for 'My Odido' portal
• Call logs and location data
• Billing information and invoice details
• Scans of identification documents

Ethical hacker Sijmen Ruwhof emphasized the severity of this breach: 'I cannot think of a company where so much data has been leaked. The combination of passport numbers with IBAN details is particularly unique and sensitive.'

Why This Data is 'Gold Worth for Criminals'

The stolen information represents an unprecedented treasure trove for cybercriminals, according to security experts. The combination of personal identifiers, financial information, and government ID numbers creates multiple avenues for exploitation:

Sophisticated Phishing Attacks

Criminals can use the authentic personal details to create highly convincing phishing emails and SMS messages. 'Because they have real data about you, such messages look very authentic and credible,' warns Ruwhof. This enables criminals to trick victims into clicking malicious links that lead to fake login pages designed to steal additional credentials.

Identity Theft and Financial Fraud

With IBAN numbers and identification documents, criminals can impersonate victims to open new accounts, apply for loans, or make fraudulent purchases. The 2025 bank heist techniques could be adapted using this stolen data, creating significant financial risks for affected individuals.

Intelligence Gathering

Cybersecurity expert Matthijs Koot notes the data represents a 'goldmine for hostile intelligence services' who could use it to map potential targets including politicians, government employees, and critical infrastructure workers. This breach follows concerning patterns seen in other EU cybersecurity incidents targeting sensitive personal information.

Company Response and Investigation

Odido discovered the breach over the weekend of February 7-8 and immediately reported it to the Dutch Data Protection Authority (AP). The company has engaged external cybersecurity experts to investigate the incident and implement additional security measures.

Odido CEO Tisha van Lammeren stated: 'We started informing our customers at 12:00 pm today. This happened from the moment it was clear at customer level which data was stolen per customer.' She explained the notification delay: 'You don't want to share incorrect information.'

The company has not confirmed whether ransom was demanded or if extortion attempts were made, stating only that customer safety remains their top priority.

What Affected Customers Should Do

Cybersecurity experts recommend the following immediate actions for Odido customers:

1. Monitor Financial Accounts: Regularly check bank statements for unauthorized transactions
2. Beware of Phishing: Be extremely cautious of emails or messages referencing your personal details
3. Enable Two-Factor Authentication: Add extra security layers to important accounts
4. Consider Credit Monitoring: Services that alert you to suspicious activity can provide early warnings
5. Report Suspicious Activity: Contact your bank and authorities immediately if you suspect fraud

Broader Implications for Cybersecurity

This massive breach highlights systemic vulnerabilities in critical infrastructure systems and raises serious questions about data protection standards in the telecommunications sector. The incident comes amid growing concerns about digital privacy regulations and their enforcement across Europe.

Experts criticize Odido's security measures, with Ruwhof noting: 'Six million data leaks is extremely much. At the moment the data was stolen, the cybersecurity department should have already intervened.' The breach underscores the need for stronger data protection frameworks and more robust security protocols across industries handling sensitive personal information.

Frequently Asked Questions (FAQ)

How many people were affected by the Odido data breach?

Approximately 6.2 million customer accounts were compromised, representing nearly 90% of Odido's customer base in the Netherlands.

What specific information was stolen?

The stolen data includes full names, addresses, mobile numbers, email addresses, IBAN bank account numbers, birthdates, and passport/driver's license numbers with validity dates.

Should I change my Odido password?

While Odido passwords were not compromised, it's always good security practice to regularly update passwords and enable two-factor authentication where available.

How can I protect myself from identity theft?

Monitor your financial accounts closely, be skeptical of unsolicited communications, consider credit monitoring services, and report any suspicious activity immediately to your bank and authorities.

Has Odido confirmed if ransom was demanded?

Odido has not publicly confirmed whether the hackers demanded ransom or attempted extortion, stating only that they are investigating all aspects of the breach.

Sources

NOS: Gestolen data bij Odido zijn 'goud waard voor criminelen'

Dutch News: Hackers access Odido customer info

NL Times: Odido cyber attack affects 6.2 million

Wikipedia: Odido company information