Police warn: if your password is on this list, change it now

Spain's National Police have issued a new warning about passwords that already appear in public leak lists. If yours is one of them, they urge you to change it immediately and strengthen your online security.

Police alert over leaked and weak passwords

The National Police have used their social media channels to draw attention to a risk that many users still underestimate: passwords that are already circulating in public databases compiled after data breaches and hacks.

These lists contain millions of real passwords stolen from online services over the years, and cybercriminals use them as a starting point when trying to break into accounts through automated attacks.

The message from the police is blunt: if a password you currently use appears in one of these compilations, you should not keep it or reuse it anywhere else.

A compromised password is effectively burnt; from a security point of view it offers almost no protection, even if it still works to log into your accounts.

Why appearing in a list is so dangerous

Public lists of leaked passwords do not just expose a few unlucky users; they also reveal the patterns that people tend to choose, such as 123456, qwerty, password, your name and date of birth, or football teams and band names.

Attackers feed these lists and patterns into tools that can test thousands or millions of combinations per minute, dramatically increasing the chances of guessing your credentials if you rely on something common or previously exposed.

In practice this means that a password can be weak for two different reasons: because it is short and easy to guess, or because it is long but already known due to a previous leak.

That is why the police and security experts insist that simply feeling attached to a password or finding it easy to remember is not a valid reason to keep it once it has appeared in a public list.

How to check whether your password has been leaked

The police point users towards well known tools and features that allow you to see whether your credentials have appeared in known breaches without exposing your current password again.

These services work by comparing a scrambled version of your password or email address against large databases of compromised data, and then telling you whether there is a match.

Some practical options include online breach checking services that let you see whether your email or password is part of known leaks, security recommendations built into modern browsers that flag reused or compromised passwords, and alerts from websites that reject passwords already present in public lists.

The key idea is that you should treat any positive result as a red alert, not as a curiosity: it means your current credentials are already part of attackers' dictionaries.

What to do if your password is on a list

If you discover that one of your passwords appears in a leak list or has been flagged as compromised, the first step is to change it immediately for that service.

You should create a new password that you have never used before, and avoid small cosmetic changes such as adding a number at the end of the old one, which are easy for attackers to predict.

It is also important to check whether you reused that same password on other websites, email accounts, social networks, cloud storage or online shops.

If you did, you must update it everywhere, because once one service has been breached, attackers often try the same email and password combination on many others in what is known as credential stuffing.

Finally, the police recommend turning on two factor authentication wherever possible, so that even if someone obtains your password they still need a second code, usually sent to your phone or generated by an app, to complete the login.

How to choose safer passwords from now on

Beyond reacting to specific alerts, the National Police and cybersecurity professionals stress the need to adopt stronger habits when creating and storing passwords.

Good practices include using long, unique passwords for each service, mixing letters, numbers and symbols, and avoiding any reference to personal data that can be guessed from social networks, such as birthdays, pet names or favourite teams.

Because it is almost impossible to remember dozens of complex passwords, they also highlight the value of password managers, which can generate and store strong credentials for each site and protect them with a single master key.

Combined with multi factor authentication and regular checks for compromised accounts, these tools sharply reduce the chances that a leaked or guessed password will lead to identity theft, financial fraud or the loss of private information.

The police warning is ultimately a reminder that online security is not static: a password that was acceptable a few years ago may now be circulating in attackers' lists, and the only way to stay ahead is to review and update your credentials regularly.