2-factor authentication is an important safeguard to prevent unauthorized account access, but does 2-factor authentication stop phishing attacks?

What is 2-Factor Authentication?

2-Factor authentication is commonly used as an additional protection measure to prevent accounts from being accessed by unauthorized individuals in the event that a password is compromised.

If a password is disclosed in a phishing attack or has otherwise been obtained or guessed, a second authentication method is required before the account can be accessed.

Two-factor authentication uses a combination of two different methods of authentication, commonly something a person owns (device/bank card), something a person knows knows (a password or PIN), and/or something a person has (fingerprint, iris scan, voice pattern, or a token).

The second factor control is triggered if an individual, authorized or otherwise, attempts to login from an unfamiliar location or from a device that has not previously been used to access the account.

For instance, a person uses their laptop to connect from a known network and enters their password. No second factor is required. The same person uses the same device and password from an unfamiliar location and a second factor must be supplied. If the login credentials are used from an unfamiliar device, by a hacker for instance that has obtained a username and password in a phishing attack, the second factor is also required.

A token or code is often used to verify identity, which is sent to a mobile phone. In such cases, in addition to a password, an attacker would also need to have the user’s phone.

Does 2-Factor Authentication Stop Phishing Attacks?

So, does 2-factor authentication stop phishing attacks from succeeding? In many cases, it does, but 2-factor authentication is not infallible. While it was once thought to be highly effective at stopping unauthorized account access, opinion is now changing. It is certainly an important additional, low-cost layer of security that is worthwhile implementing, but 2-factor authentication alone will not prevent all phishing attacks from succeeding.

There are various methods that can be used to bypass 2-factor authentication, for instance, if a user is directed to a phishing page and enters their credentials, the hacker can then use those details in real-time to login to the legitimate site. A 2FA code is sent to the user’s device, the user then enters that code into the phishing page. The attacker then uses the code on the legitimate site.

This 2-factor authentication bypass is somewhat cumbersome, but this week a phishing tool has been released that automates this process. The penetration testing tool was created by a Polish researcher named Piotr Duszynski, and it allows 2FA to be bypassed with ease.

The tool, named Modlishka, is a reverse proxy that has been modified for handling login page traffic. The tool sits between the user and the target website on a phishing domain. When the user connects to the phishing page hosting this tool, the tool serves content from the legitimate site – Gmail for instance – but all traffic passes through the tool and is recorded, including the 2FA code.

The user supplies their credentials, a 2-factor code is sent to their phone, and that code is entered, giving the attacker account access.

It is an automated version of the above bypass that only requires a hacker to have a domain to use, a valid TLS certificate for the domain, and a copy of the tool. No website phishing templates need to be created as they are served from the genuine site. Since the tool has been made available on Github, the 2FA bypass could easily be used by hackers.

Additional Controls to Stop Phishing Attacks

To protect against phishing, a variety of methods must be used. First, an advanced spam filter is required to prevent phishing emails from reaching inboxes. SpamTitan, for instance, blocks more than 99.9% of spam and phishing emails.

Fewer than 0.1% of emails may make it past the spam filter, but any one could result in an account compromise. Security awareness training should therefore be provided to employees to help them identify suspicious emails.

Unfortunately, people do make mistakes and phishing emails can be highly realistic, so it is wise to also implement a web filter.

A web filter will block attempts to connect to known phishing sites and can assess sites in real time to help determine their authenticity. If the checks fail, the user will be prevented from accessing the site.

These anti-phishing controls are now essential cybersecurity measures for businesses to protect against phishing attacks, and are all the more important since 2FA cannot be relied upon to protect against unauthorized access once a password has been compromised.

You can find out more about SpamTitan and WebTitan by contacting TitanHQ.