How to Prevent Phishing Attacks

A typical way of getting hacked is falling for a phishing attack. In fact, most of the large data breaches in recent years have been due to phishing.

The number of phishing attacks is increasing because they are both easy to execute and highly effective. Even if the eventual goal of an attacker is an organization, attacks always begin by targeting individuals. Phishing attacks have been utilized to steal confidential information, compromise entire organizations, and perhaps even influence a Presidential election.

What is a phishing attack?

Phishing is a type of online attack where criminals send a fake email asking you to click a link or download an attachment, appearing to be from a legitimate source. That can be a bank, a credit card company, an email provider or popular services like Google, Ebay, or Facebook.

Phishing campaigns can be extremely sophisticated, making use of highly personalized messages that appear to come from people you know, or companies you trust. Oftentimes, attackers will try to trick you into entering your password into a web page that appears legitimate but is actually a fraudulent site which is stealing your data.

Phishing attacks can also rely on malicious software. Instead of trying to trick you into entering your password, these attacks will try to trick you into clicking on a link to an infected website, or opening an infected file, or installing malicious software on your device. For example, an attacker pretending to be your bank might ask you to review recent transactions and send over a file of recent transactions. However, opening the file will install a virus on your computer.

Defending against email phishing attacks

Fortunately, it’s not difficult to defend against phishing attacks as long as you are vigilant and comply with the following rules. These rules are generally applicable and aren’t specific to ProtonMail. But as you will see below, ProtonMail has several additional anti-phishing protections built in, which make it much harder to become a victim.

Protect your email address

In order to start an attack against you, attackers must first know your email address. You can’t hide your address, however, you can keep separate email addresses for different purposes. For example, don’t use your business card email address for your bank account, loan or other sensitive accounts. Choose a secure, secret one.


With ProtonMail you can use multiple addresses to keep your private address a secret. For example, if the address you use in public is, you can create a second address to use only for sensitive accounts like online banking. Thus, if somebody pretending to be your bank sends you an email to, you can identify it as a phishing email because it was not sent to the address you use for your online banking.

Carefully verify the emails you receive

Always check that the sender is who they say they are. Phishing emails can usually be easily identified because they rarely get everything right:

  • the sender of the email will usually not be an official communication account. For example, a phishing email targeting ProtonMail users might be sent from
  • the link contained in the phishing email will also not be an official site either. For example, the link in the email might go to instead of ProtonMail offers a link confirmation feature that can help you verify the link you are following is not malicious.
  • emails can also come from people that you know, but with subtle variations instead of (can you see the difference?)

Note, these accounts and URLs will sometimes look deceptively similar to the real thing, so be sure to check them carefully!


Keep in mind that communications from ProtonMail will always come from one of the following Official ProtonMail Accounts:

  • (other very rarely used accounts include,,,,,

And we only make use of the following domains:, As an added protection, automated messages from the ProtonMail Team are always starred by default.


ProtonMail Email Phishing Protection

ProtonMail provides additional anti-phishing protection with PhishGuard, a set of special features designed specifically to combat phishing.

Because sender email addresses can be spoofed (e.g. an email can appear to come from but not actually be sent from there), ProtonMail provides an additional way to help identify whether an email is legitimate.

If the person you are communicating with is also using ProtonMail (or their email is hosted by ProtonMail), your communication is transmitted with end-to-end encryption. Secure emails sent from other ProtonMail users can be identified by the purple lock.


Sender spoofing is NOT possible between ProtonMail addresses or domains hosted by ProtonMail. Thus, if the “From” address is, and it has a purple lock, you can be sure it is actually sent from that account.

This also means that if your organization’s emails are hosted by ProtonMail, the purple lock guarantees that:

  • The email was sent by another member of your organization
  • The address is not spoofed (and therefore it is most likely not a phishing email).

These features means the phishing risk for you or your business is greatly reduced if you are using ProtonMail.

DMARC Protection

To further protect users, ProtonMail also supports DMARC which helps to identify emails which might be spoofed. For example, when you open an email which fails DMARC, we display a red warning message to warn you that the email may be spoofed and that you should verify the authenticity of the email with the sender.

email dmarc spoofing
An example of how an email that fails DMARC is displayed in ProtonMail.

Link confirmation

Hackers do not always need to fool you into sharing sensitive data. If they can deceive you just long enough for you to click on a malicious link, they can still compromise your device’s security. To prevent this, ProtonMail’s Link Confirmation can help you identify suspicious links without putting your device at risk. When Link Confirmation is enabled, a window will pop up whenever you click on a hyperlink contained in a message. That pop-up displays the link’s full URL, giving you a chance to inspect whether the link is suspicious. 

Protect your passwords

No organization in possession of sensitive data should EVER ask for your password via email. If you receive an unsolicited email asking you for your password, or with a link taking you to a suspicious looking website asking you for your credentials, do NOT enter your password.

ProtonMail will never send you unsolicited emails or other communication asking you for your ProtonMail credentials. We may occasionally ask you for login details and information if you are experiencing a login problem, but only if you initiated communication with our support team.

Report phishing emails to our support team

If you receive an email you suspect to be a phishing attack, do not click on any links or download any attachments. Instead, we have created a simple way to report the email to our support team, which will analyze the headers and contents to improve our spam filters. (Note that emails reported to us as phishing will be sent to our team unencrypted.) Learn how to use our report phishing feature.

What to do if you’ve been hacked

If you’ve fallen for a phishing scam, there are a few things you should do immediately to recover and protect your account.

  1. Go to Settings -> Account and verify that the Reset/notification email has not been changed or added by the hacker.
  2. On the same Account page, change your password.
  3. Then go to Settings -> Security and enable two-factor authentication (2FA). This ensures that the hacker (and future hackers) cannot break into your account without also having access to your 2FA device.
  4. On the same Security page, enable Advanced Authentication Logs, which allow you to track when and from where someone has accessed your account or tried to.
  5. You can also check your other settings to be sure nothing has been tampered with. For instance, an attacker might whitelist their own email addresses, add spammy links to your email signature, or set up auto replies to trick your contacts.

When in doubt, Ask!

If you have any doubts about whether or not an email is legitimate, please ask and confirm with the person or company that supposedly sent it. In the case of a suspicious email that claims to be from the ProtonMail Team, you can write to and our security team will be able to advise you further.

You can get a free secure email account from ProtonMail here.

ProtonMail is supported by community contributions. We don’t serve ads or abuse your privacy. You can support our mission by upgrading to a paid plan or donating.

About the Author

Proton Team

Proton was founded by scientists who met at CERN and had the idea that an internet where privacy is the default is essential to preserving freedom. Our team of developers, engineers, and designers from all over the world is working to provide you with secure ways to be in control of your online data.