This article explains why, in a ransomware simulation, the teachable moment may show the text without the images when the user opens the downloaded file on a mobile phone. It also explains how to fix it.
When it happens
In ransomware simulations, the teachable moment can be displayed at different points of the simulation. This issue only occurs when the teachable moment is displayed when the downloaded file is opened.
If the teachable moment is displayed at another point, for example when the file is downloaded, the issue does not occur. In that case, the link in the email opens directly in the phone's browser and the images load normally.
When the downloaded file is opened on a mobile phone, the operating system chooses an app to display it. If that app is an HTML viewer instead of a browser, the teachable moment is displayed incompletely:
- The text is displayed correctly.
- An image not available icon appears instead of each image.
The same user, in the same teachable moment, can see the full content on a computer or in a mobile browser.
The content and images of the teachable moment work correctly. The difference depends on the app used to open the file on the device.
Why it happens
The images of the teachable moment are hosted online. To display them, the app that opens the file must download them.
- Browser (Chrome, Firefox, Safari, Samsung Internet): downloads every element of the page, including the images. The teachable moment is displayed in full.
- HTML viewer: an app designed to display files stored on the device. For security reasons, it usually does not download external resources. It displays the text, but not the images.
How to fix it
Open the file with a browser
- Ask the user to open the downloaded file again.
- If the phone asks which app to use, the user must select a browser, for example Chrome.
Remove the HTML viewer as the default app
If the phone opens the file directly with the HTML viewer, without asking, the user can remove it as the default app:
- Go to Settings > Apps.
- Select the HTML viewer.
- Go to Open by default.
- Select Clear defaults.
From then on, the phone will let the user choose which app to open the file with.
The names of these options may vary depending on the phone brand and operating system version.
💡 Best practices
- Recommend that users open downloaded files with a browser when using a mobile phone.
- Ask the user for a screenshot to confirm the symptom. An image not available icon in place of each image indicates this case.
- Check the same teachable moment in a browser before reporting an issue with the content.