Phishing is mostly conducted via email; however, a recent data breach at the cloud communication company Twilio demonstrates that phishing can be highly effective when conducted using other popular communication methods, such as SMS messages.

An SMS phishing attack – known as SMiShing – involves sending SMS messages with a link to a malicious website with some kind of lure to get people to click. Once a click occurs, the scam progresses as an email phishing attack does, with the user being prompted to disclose their credentials on a website that is usually a spoofed site to make it appear genuine. The credentials are then captured and used by the attacker to remotely access the victims’ accounts.

Twillio provides programmable voice, text, chat, video, and email APIs, which are used by more than 10 million developers and 150,000 businesses to create customer engagement platforms. In this smishing attack, Twilio employees were sent SMS messages that appeared to have been sent by the Twilio IT department that directed them to a cloned website that had the Twilio sign-in page. Due to the small screen size on mobile devices, the full URL is not displayed, but certain keywords are added to the URLs that will be displayed to add realism to the scam. The URLs in this campaign included keywords such as SSO, Okta, and Twilio.

According to Twilio EMEA Communications director, Katherine James, the company detected suspicious account activity on August 4, 2022, and the investigation confirmed that several employee accounts had been accessed by unauthorized individuals following responses to the SMS messages. The attackers were able to access certain customer data through the Twilio accounts, although James declined to say how many employees were tricked by the scam and how many customers had been affected.

Twilio was transparent about the data breach and shared the text of one of the phishing emails, which read:

Notice! [redacted] login has expired. Please tap twilio-sso-com to update your password!

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The text messages were sent from U.S. carrier networks. Twilio contacted those companies and the hosting providers to shut down the operation and take down the malicious URLs. Twilio said they were not the only company to be targeted in this SMS phishing campaign, and the company worked in conjunction with those other companies to try to shut the operation down; however, as is common in these campaigns, the threat actors simply switch mobile carriers and hosting providers to continue their attacks.

The smishing attack and data breach should serve as a reminder to all businesses of the risk of smishing. Blocking these types of phishing attacks can be a challenge for businesses. The best starting point for improving your defenses is to provide security awareness training for the workforce. Security awareness training for employees usually has a strong emphasis on email phishing, since this type of phishing is far more common, but it is important to also ensure that employees are trained on how to recognize phishing in all its forms, including smishing, social media phishing, and voice phishing – vishing – which takes place over the telephone.

The easiest way to do this is to work with a security vendor such as TitanHQ. TitanHQ offers a comprehensive security awareness training platform – SafeTitan – with an extensive range of training content on all aspects of security, including smishing and voice phishing. The training content is engaging, interactive, and effective at improving cybersecurity understanding, and SafeTitan is the only security awareness training platform that delivers training in real-time in response to the behavior of employees. The platform also includes a phishing simulator for automating simulated phishing tests on employees.

For more information about improving security awareness in your organization, contact TitanHQ today.