Mobile Messaging Service Abused for Phishing

By Zachary Bailey, Cofense Phishing Defense Center

Using Cofense Vision, analysts at the Cofense Phishing Defense Center (PDC) were able to drill down into the targeting patterns of one phishing campaign that leveraged Verizon’s multimedia messaging service – Vzwpix. On its own, Vzwpix allows Verizon customers to send their texts as emails to recipients, which will then be delivered to their inbox rather than phone messages. Most phone providers have a similar service offered, but the benefits of this utility go beyond just convenience. Threat actors can utilize these services to mass deliver texts that come from a phone number, but not show the name of the sender. This can leave recipients guessing who sent them if they do not recognize the number. Hesitant users have the option to report these messages to the Cofense PDC for further analysis to ensure they are benign.

In recent weeks, the Cofense PDC received hundreds of reports for Verizon’s Vzwpix service domain. Most of these are non-malicious texts or images, but reporters are always vigilant of potential threats. This week, customers in a variety of different industries were targeted by threat actors using Vzwpix.

Figure 1: Email Body

In Figure 1, it can be seen that the received message is a simple text without any styling or images. It references a new voicemail and uses a financial lure involving ACH transfers. The link is displayed as plain text, letting users know exactly where they will go. It was able to evade initial analysis from the secure email gateway (SEG) by using a legitimate survey application; however, some SEGs would be able to check the content of the survey via link-click. Here, the threat actors leveraged Alchemer, a survey form builder that makes it easy to create a survey for users to fill out. Threat actors have used various survey sites to quickly generate simple quizzes/forms asking users for their account information. These templates allow custom backgrounds and images, speeding up the rollout of their new phishing pages.

Figure 2: Phishing Page (Desktop View)

Graphical user interface, application Description automatically generated

Figure 3: Phishing Page (Mobile View)

In Figure 2, the survey is incorrectly formatted as a OneDrive login page and most users would suspect this is not a legitimate Microsoft OneDrive login page. The continue button is also off to the side, making the page look like it was not designed to be viewed through a PC web browser. When switching to a mobile device, shown in Figure 3, there is a clear difference between the layouts of the form. The resized phishing page is drawn within the white box and the button is aligned with the entry fields. A user on a mobile device might not notice this is not the Microsoft site at first given the ease in which they can interact with the form. However, typical indicators of phish remain such as an easily viewable wrong address in the address bar.

Figure 4: Targeted Companies

Using Cofense Vision, analysts were able to identify multiple employees who received the same message at their company. Even though each message came from the same phone number, they all had different message IDs. In Figure 4, we can see a portion of the results found clustered by these unique indicators, which were exported from Cofense Vision. These message IDs are related to the Verizon phone number that sent out the messages. Each message ID corresponds to a different group of recipients that were in the “To” address of the email.

Figure 5: Industries Represented by Percentage for Manufacturing Customer

By analyzing these clusters, we can discover new trends in how these seemingly unrelated recipients were targeted. At first glance, each cluster had a minimum of ten email addresses including PDC customers and external domains. Several clusters had multiple emails targeting the same domain, indicating a possibility that these were likely not sent at random but were from a list of targets by industry. By stripping out just the unique domains, it can be determined that 50% of all recipients were in the food manufacturing industry, shown in Figure 5. The PDC customer targeted in these clusters is in the manufacturing industry, but one of its primary subsidiaries is involved in food manufacturing. Supply chain and media companies make up another 25% of the targeted domains.


Figure 6: Industries Represented by Recipient for Financial Customer

The remaining PDC customers targeted by this campaign did not have Cofense Vision but reviewing the reports of one customer shows a similar trend. This customer is in the financial industry and, as shown in Figure 6, 60% of the other domains contacted are also in the financial industry, with 25% being in the legal industry.

When an organization leverages Cofense Vision, your SOC team can leverage these searches to identify if any of your business partners are also targeted and manually alert them. The Cofense network effect allows the actions of one reporter to shield our customers from threats, and since Cofense sits behind any SEG, a new tactic used that might slip into an employee’s inbox can be remediated with a single click before they know it is there. Reach out us to learn more about Cofense Vision and the PDC.

Indicators of Compromise IP
All third-party trademarks referenced by Cofense whether in logo form, name form or product form, or otherwise, remain the property of their respective holders, and use of these trademarks in no way indicates any relationship between Cofense and the holders of the trademarks. Any observations contained in this blog regarding circumvention of end point protections are based on observations at a point in time based on a specific set of system configurations. Subsequent updates or different configurations may be effective at stopping these or similar threats. Past performance is not indicative of future results.
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Latest Cofense Triage Release Includes Powerful Reporting, Communication and Data Analysis Improvements

Cofense’s Q2 2021 Phishing Review uncovered that, to no surprise, the volume of phishing emails is trending up year over year. More phishing emails means (hopefully) more emails sent to your security team to investigate and protect against. The importance of prioritizing and responding to those emails is more important than ever and Cofense Triage is a trusted partner in doing so. As one of our operators put it, “Triage enables analysts to easily investigate reported emails safely and efficiently. It has assisted in preventing numerous phishing campaigns.”

Here at Cofense we’re always listening and collaborating with our operators. Based on the feedback we’ve received, we’re excited to bring you the latest edition of Cofense Triage: Triage 1.23.

Cofense Triage 1.23 introduces the following new capabilities:

  • Customizable report templates and automated sharing of reports
  • Improved response and notification template editor and management interface
  • Enhanced Cofense Vision integration experience
  • Support for a variety of URL decoders

Do we have your attention? Great! Keep reading for details on each.

Report on what you want, how you want, when you want

Reporting on operational and proof of value metrics is critical to security professionals. Each organization has its own priorities and requirements, and needs the ability to quantitatively report on the value that the security software is providing to the organization.

In this latest release of Cofense Triage, we give operators and managers more reporting options with more than 20 key metrics and data visualization (charts, graphs, tables) available for each. Create templates with only the desired topics, determine the interval for automatic report generation or run ad hoc reports, and set the order for how Triage displays the report charts in an improved, interactive, reports interface.

Figure 1: Create Report Templates via an Easy-to-use Builder

And we didn’t stop there. Reporting on metrics is great, but sharing those insights is even better. Download the report as a Microsoft Excel workbook or a JSON object for sharing, or have Triage email the workbook to individuals or distribution lists.

This can happen at regularly scheduled intervals giving organizations the data they need to better understand their security program’s performance, saving valuable time through automated report generation and sharing.

Provide templated automated updates in real time as investigation happens

Getting all employees involved in an organization’s phishing prevention and response strategy is a big key to success. Once they’ve done their due diligence and reported a potential phish, sending updates to keep them informed could be the positive reinforcement they need. The days of this being time consuming and burdensome are gone. Now, send reporters automated response emails that include organizational-specific attributes displayed in a predictable and expected way – not require human intervention to make sense of things.