Billions of compromised credentials are circulating on the internet. They originate from data leaks, phishing attacks, infostealer malware, and other attacks, and are sometimes combined into massive data collections.<\/p>\n\n\n\n
In 2025, a particular amount of attention was received by a collection of around 16 billion login records<\/strong>. However, this was neither a single new attack nor 16 billion different affected individuals. The data came from various sources and also contained duplicates.<\/p>\n\n\n\n For users and companies, the exact number is secondary anyway. The decisive factor is: Stolen credentials can still be used for attacks \u2013 especially when passwords are reused.<\/strong><\/p>\n\n\n\n Such collections of passwords and credentials usually do not come from a single major hacker attack. Instead, data from various sources is collected and later combined.<\/p>\n\n\n\n Typical sources are:<\/p>\n\n\n\n Particularly problematic are so-called Infostealer<\/strong>. Among other things, these malicious programs attempt to read access credentials stored in the browser or on the device and transmit them to attackers.<\/p>\n\n\n\n A stolen password does not only have to be dangerous for the service originally affected.<\/p>\n\n\n\n Anyone who uses the same password for multiple accounts may turn a single data breach into a problem for numerous other logins.<\/strong><\/p>\n\n\n\n Attackers can automatically try known combinations of email address, username, and password on other services. This attack method is called Credential Stuffing<\/strong> referred to as.<\/p>\n\n\n\n If, for example, the same password works for the online shop, the cloud service, and the email account, a single compromised access point can have far-reaching consequences.<\/p>\n\n\n\n The email account is one of the most important digital access points of all. It is used to reset passwords, send confirmations, and exchange both business and personal information.<\/p>\n\n\n\n A compromised email account can, among other things:<\/p>\n\n\n\n Particularly for companies, this can quickly become a significant security problem. In addition to secure access data, spam, phishing, and malware protection therefore also play an important role. You can find out more about this at our Email security solutions<\/strong><\/a>.<\/p>\n\n\n\n You don't have to wait for the next report of a major data breach. With a few basic measures, the risk of compromised accounts can be significantly reduced.<\/p>\n\n\n\n Never use the same password for multiple important accounts. Email, hosting, cloud services, payment providers, and administrative access in particular should each have their own strong password.<\/p>\n\n\n\nWhere do the compromised credentials originate?<\/h2>\n\n\n\n
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Why reused passwords are so dangerous<\/h2>\n\n\n\n
Why the email account should be particularly protected<\/h2>\n\n\n\n
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What you should do now, specifically<\/h2>\n\n\n\n
1. Use a separate password for each service<\/h3>\n\n\n\n