MetaDefender Core Customer Snapshot


Upwork is a freelancing website that connects businesses with freelance talent for highly-skilled knowledge work such as web, mobile and software development and design. Through Upwork businesses get more done, connecting with freelancers to work on projects from web and mobile app development to SEO, social media marketing, content writing, graphic design, admin help and thousands of other projects. Upwork makes it fast, simple, and cost-effective to find, hire, work with, and pay the best professionals anywhere, any time.

Customer Challenges

Upwork receives millions of files a day from clients and freelancers and needs to ensure that those files are free from threats to protect both their own systems and the systems of everyone using their platform. Clients upload many files to Upwork’s platform throughout the process of posting open positions, interviewing and filling those positions, and communicating project requirements. Freelancers also upload files to share their resumes, apply for positions, and deliver their finished product to clients. 

OPSWAT’s Solution

The OPSWAT MetaDefender product line provides industry-leading protection against known and unknown threats by combining multi-scanning, content disarm and reconstruction (CDR, also known as data sanitization), and vulnerability assessment. Upwork uses MetaDefender to scan all files when they are uploaded to ensure they do not contain malware. Prior to their deployment of MetaDefender, Upwork was not able to detect and block malicious files that were uploaded to the platform. After scanning files with MetaDefender’s multiple anti-malware engines, Upwork uses MetaDefender’s data sanitization technology to remove potentially malicious elements from files.

Upwork has always been focused on providing a secure environment for its community of millions of users, so they can safely transfer files and collaborate. Upwork and OPSWAT’s mutual commitment to security reinforces our pledge to ensure all users can have the necessary protection to keep their home and business IT environments safe.

Teza Mukkavilli
Head of Security, Upwork

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Upwork first implemented MetaDefender’s multi-scanning, which was successful in detecting and blocking many threats, but found that although known threats were getting blocked there were still some new threats that were not detected by any of the anti-malware engines. Upwork then chose to add data sanitization to the MetaDefender security rules used to process uploads, enabling data sanitization for all supported file types. Since data sanitization was implemented, there have been no reported instances of threats making it through MetaDefender’s processing.

MetaDefender’s data sanitization process uses two methods to sanitize supported files. The first is Content Disarm and Reconstruction (CDR), in which the file is broken down into its component parts, and any potentially malicious components (e.g. macros, scripts, or embedded files) are removed. The file is then reconstructed with the remaining safe content. The other method used is file type conversion, in which files are converted from one file format to another (e.g. JPEG to GIF). The conversion process retains the safe content of the file while removing any malicious payload that might be hidden within the file. Upwork utilizes both of these data sanitization methods.

Because the user-uploaded files are modified by the data sanitization process, Upwork retains the original file in case something is lost during the sanitization process that is critical to the value of the file. In the time since implementation of the data sanitization functionality, however, no user of Upwork’s platform has requested access to the original file. This is a strong endorsement of MetaDefender’s ability to retain the usability of files throughout the data sanitization process.

“We are proud that Upwork uses MetaDefender to ensure the safety of the files uploaded by all of the users of their platform,” Tony Berning, OPSWAT’s Senior Product Manager for MetaDefender, commented. “Upwork’s business depends on allowing all of their users to upload and share files and MetaDefender allows this to happen while reducing the inherent risk in using files from such a diverse set of sources.”

For more information about OPSWAT and the MetaDefender product line, please contact us.


OPSWAT is a San Francisco-based cyber security software company that provides solutions to secure and manage IT infrastructure. Founded in 2002, OPSWAT has delivered solutions and technologies that protect organizations from threats and secure digital data for over a decade. OPSWAT combines next-generation Content Disarm and Reconstruction technology, its cutting-edge Vulnerability Engine, and multi-scanning with over 30 anti-malware engines in its MetaDefender suite of products, and its OESIS Framework endpoint security SDK has helped secure over 200 million endpoints. To learn more about OPSWAT, visit