Cloudinary Blog

How To Prevent Malware And Detect Infected User Uploads

How To Prevent Malware in Malicious File Upload

Social networking sites allow users to upload images or other types of files that are immediately available to other users via news feeds or notifications. In some cases, attackers can directly spread infected files, but more commonly, they leverage the viral effect and the fact that users are simply unaware that their files are infected through sharing and collaborating with others. As a site owner or application developer, it is your responsibility to protect users and prevent these situations from occurring. Fortunately, Cloudinary makes this easier with its Metascan add-on.

How to prevent malware in malicious file upload

Cloudinary's image management allows you to file upload, along with other files like PDFs, directly from your users’ browsers or mobile applications. While most modern image formats are fairly safe, nothing is guaranteed, and the various other file formats that users use to upload and share may be infected with malicious code. We want to ensure that you and your users are safe so that there's no chance of malware creeping into uploaded files. With Cloudinary's Metascan add-on, you can detect and prevent advanced known and unknown malware and threats by scanning and sanitizing your users' uploaded files.

Webinar
How to Optimize for Page Load Speed

Metascan anti-malware add-on

Brought to you by OPSWAT, Metascan is fully integrated into Cloudinary’s image management and transformation service. While uploading images to the cloud using Cloudinary’s upload API, you can set the moderation upload API parameter to metascan in order to request to have your uploaded images and other files automatically scanned and removed if malware is detected. It’s also possible to select batches of previously uploaded files to scan using Cloudinary’s API.

With the Metascan add-on, you don't need to install any anti-malware software or build a file scanning pipeline. By simply using Cloudinary's image upload API, or Admin API for previously uploaded images, all of your images can be scanned and moderated accordingly.

Below is a sample code that requests a Metascan scan of a PDF document that is being uploaded to Cloudinary.

Ruby:
Copy to clipboard
Cloudinary::Uploader.upload("local_file.pdf", 
  :moderation => "metascan")
PHP:
Copy to clipboard
\Cloudinary\Uploader::upload("local_file.pdf", 
  array("moderation" => "metascan"));
Python:
Copy to clipboard
cloudinary.uploader.upload("local_file.pdf",
  moderation = "metascan")
Node.js:
Copy to clipboard
cloudinary.uploader.upload("local_file.pdf", 
  function(result) { console.log(result); }, 
  { moderation: "metascan" });
Java:
Copy to clipboard
cloudinary.uploader().upload("local_file.pdf", 
  ObjectUtils.asMap("moderation", "metascan"));

With this request, Metascan performs scans with anti-malware engines (ESet, AVG, ClaimWin and Norman) on images and files that are being uploaded. Scanning is done asynchronously within seconds, meaning there is no impact on user experience. If Metascan detects malware in a file, the file is removed and the CDN cache is invalidated. The original file is stored in secondary storage, which enables you to recover it in case you want to override the Metascan results.

Additionally, you can set up notifications that let you know which files were marked as safe or rejected. You have the option of scanning your user uploaded files with Cloudinary before publishing them, allowing you to share only uploaded content that you know has gotten the green light.

As you can see in the screenshot below, Cloudinary’s online media library allows you to further control this process with multiple lists of pending scan requests, and approved or rejected files, permitting you to override these results if necessary. These can also be performed by the API. For example, if a user reports a file that wasn’t initially found to be malicious, you can mark it as problematic with a single click or API call and remove it or approve it if you think that it was mistakenly marked as containing malware. See our documentation to learn more about the Metascan add-on.

Metascan moderation queue

Final Notes

With all of the cyber threats in the world today, sharing on social networks makes malware distribution fast and dangerous. While most image formats are relatively safe, other formats, such as PDFs, are more risky. At Cloudinary, we are committed to helping you protect your users, website or web application from malware and viruses. Using Cloudinary’s Metascan add-on prevents vulnerabilities and enhances overall site security.

Metascan add-on screenshot

You can try the Metascan add-on for free, just by subscribing to the free add-on plan. If you don't have a Cloudinary account yet, sign up for a free account here.


Further Reading on File Upload

Recent Blog Posts

Automatically Translating Videos for an International Audience

No matter your business focus—public service, B2B integration, recruitment—multimedia, in particular video, is remarkably effective in communicating with the audience. Before, making video accessible to diverse viewers involved tasks galore, such as eliciting the service of production studios to manually dub, transcribe, and add subtitles. Those operations were costly and slow, especially for globally destined content.

Read more
Cloudinary Helps Minted Manage Its Image-Generation Pipeline at Scale

David first shared his thoughts at our ImageCon coverence last October and this case study is an abbreviated version of Minted’s success using Cloudinary.

Over time, Faithful renderings of the creations of the illustrators, textile designers, painters, packaging designers, marketers, and stay-at-home moms, all of whom are core contributors of the Minted world, was getting harder and harder. Legacy technology wasn’t cutting it any more—and it was time for Cloudinary to step in.

Read more
Highlights on ImageCon 2021 and a Preview of ImageCon 2022

New year, same trend! Visual media will continue to play a monumental role in driving online conversions. To keep up with visual-experience trends and best practices, Cloudinary holds an annual conference called ImageCon, a one-of-a-kind event that helps attendees create the most engaging visual experiences possible.

Read more

New for DAM: Media Library Extension for Chrome

By Sharon Yelenik
A New Media Library Chrome Extension for Cloudinary DAM

With the introduction of the Media Library Extension, a Chrome-browser add-on that streamlines the access to, search for, and management of images and videos, Cloudinary offers yet another effective tool for its Digital Asset Management (DAM) solution. Let’s have a look at how most teams are currently working with media assets and how the new add-on not only boosts efficiency, but also renders the process a pleasure to work with.

Read more
New Features Supercharge Cloudinary’s Digital Asset Management Solution.

Today, I’m thrilled to announce the launch of Apps for Digital Asset Management and a Media Library Extension for the Chrome browser, which enables easy, flexible integration with all web-based applications in addition to making asset discovery more robust and accessible to all.

Read more
Scale and Automate Workflows With Modern Digital Asset Management Systems

With building, growing, and maintaining a strong digital presence being a top priority for all brands, high-quality visual content is paramount. In fact, consumers are 40 times more likely to share visual content on social networks than on other forums. Plus, a recent study from Wyzowl found that 84% of consumers made purchase decisions after watching a video, which explains why many brands are adding more and more visual media to their sites.

Read more