Cloudmersive’s Virus Scan API makes enterprise-grade file scanning available as a simple cloud-based API call. Development teams can plug this API into any workflow that handles file uploads or transfers and expect to get high-quality protection against a wide range of serious file-based threats

The problem it solves is simultaneously mundane and mission-critical. Every business that processes digital files (e.g., web apps accepting resumes, cloud platforms handling massive document transfers, etc.) faces the risk that one of those files contains hidden malware. A single infected upload can cause massive problems: ransomware infections, data breaches, prolonged downtime, or any number of other costly outcomes. The Advanced Virus Scan API gives enterprise cybersecurity executives and developers the flexibility to address that risk anywhere they see fit within their own infrastructure.

In essence, it’s an enterprise security control condensed into an API endpoint. Like any API, it allows developers to stay focused on their application’s business logic while Cloudmersive handles the difficult and expensive part: continuously maintaining an updated database of threat signatures, state-of-the-art heuristics, and machine learning detection models.

This review takes a close look at the Advanced Virus Scan API’s capabilities and performance, and it evaluates this API’s fit within Cloudmersive’s larger product ecosystem.

Cloudmersive Services Overview

API-First Platform

Before we dive into our Advanced Virus Scan API review, we’ll do a brief overview of Cloudmersive services.

Cloudmersive is a relatively young company that has built its brand around a variety of API-driven utility services. While security is clearly the primary focus of their business, their full catalog spans several different verticals: file scanning, document conversion, OCR, barcode recognition, data validation, etc. among others.

Across all these services, the business model is uniform. Cloudmersive wants to take your repetitive backend functionality, abstract it away into a hardened environment, and expose it to you through developer-friendly endpoints.

They’ve certainly nailed the developer-friendly part. Accessibility is the big draw. Documentation is clean, SDKs exist for all major programming languages (C#, Java, Python, Node.js, Go, PHP, Ruby and even JavaScript), and code samples are copy-paste ready. For teams who don’t have time to build complex antivirus integrations internally (and who does?), it’s hard to argue with a service that just plain works via HTTPS call and API key.

The Advanced Virus Scan API

At its heart, the API provides two scanning modes.

• Basic Scan: Signature-based; suitable for standard antivirus workflows

• Advanced Scan: Adds heuristic analysis, AI-based analysis, and structural analysis layers; Cloudmersive brands this as “360-Degree Content Verification”

Understanding Cloudmersive’s Basic and Advanced Scanning Modes

You might notice that so far in this review, we’ve only been referring to the Virus Scan API in terms of its Advanced mode when a Basic mode also exists.

Here’s why: After doing some research into the product, I found that there’s little reason to use only the Basic version. Both services cost the same, and the Advanced version gives you everything the Basic version does.

So, why doesn’t Cloudmersive just sell the former instead of both? I can’t say for certain, but my theory is Cloudmersive presents the Basic scan as a separate option because it orients customers in the world of antivirus products they already understand. Explaining what the Advanced Virus Scan API does is a (big) mouthful of jargony information, and those advanced capabilities might seem superfluous at first for customers just starting their online search for antivirus solutions.

Ironically, the “Advanced” mode is really what differentiates the API from competition in the antivirus space. It’s built to catch the unique types of file-based threats that signature-only systems frequently miss, such as disguised executables, scripts embedded deep within MS Office documents, JavaScript buried in PDFs, malformed archives, and all kinds of corrupted binaries designed specifically to evade signature-only scanning engines.

Cloudmersive clearly thinks these are the threats most likely to hurt your enterprise in a fast-evolving threat landscape, and it’s hard to argue with that position. Sophisticated threat actors have always devised clever malware to stay ahead of the signature-based scanning curve, and with the advent of black hat LLMs for speeding up unique malware creation, it’s become much easier for less sophisticated threat actors to do the same.

Advanced Virus Scan API Requests

Advanced Virus Scan API requests are sent as standard multipart/form-data uploads, and each response returns structured JSON detailing whether certain types of threats were found, which threat rules triggered that conclusion, and what other suspicious content might’ve been nestled within the original file. Developers can drop this into any file handling pipeline and expect full file scanning and file verification functionality wrapped into one.

Deployment & Integration

Primary Deployment Options

The API can be consumed in three primary ways:

As mentioned before, connectivity is handled over HTTPs with API key authentication in all cases. There’s no requirement to manage updates to scanning engines or cluster nodes; Cloudmersive handles that continuously in the background.

Integration with Cloudmersive Security Products

It’s worth noting Advanced Virus Scan API is used in most of Cloudmersive’s flagship security products, including their virus-scanning forward or reverse proxy server, their cloud storage virus-scanning solution, and their virus-scanning ICAP server. There’s no formal API integration involved here; these products are powered by the Advanced Virus Scan API as their primary security engine (they aren’t necessarily limited to virus scanning, however – these products can also be configured to call Cloudmersive’s Content Moderation API as an additional security measure).

If you’re looking for a full-fledged antivirus product to plug into your infrastructure rather than a standalone API service, you can implement one of these API-powered products and take advantage of all the same deployment options. It’s pretty unique that they offer both options.

Performance & Accuracy

API response times are fast in day-to-day use. Customers can expect well under a second for small files, even when using the Advanced mode. Throughput scales horizontally across multiple nodes, and multi-gigabyte files are supported depending on plan limits.

The detection engine itself combines traditional signature-based scanning (signatures continuously updated from a combination of private and public malware signature databases each day) with heuristic pattern recognition and structural file analysis. Cloudmersive cites a detection rate of about 95% from third-party studies, and while that figure isn’t independently verified here, empirical testing suggests strong performance on both known-malware sets and mixed-document archives.

Zero Day Detection Rate (ZDDR)

Cloudmersive has also carried out an internal test of their Advanced Virus Scan API using a metric called Zero Day Detection Rate (ZDDR). In short, this test studied the efficiency of the Advanced Virus Scan API in detecting malware from datasets that it had not been trained to recognize (in this case, Cloudmersive used the Malware Bazaar dataset).

From the copy of this report I received, ZDDR hovered around 96% over 5 days of testing. That’s a very impressive number. I haven’t reproduced this test yet, but all the information required to reproduce this test is disclosed in their report. It’s clear Cloudmersive is confident in these results, and I’ll give them the benefit of the doubt. Here’s a snapshot of results from this test (taken from Cloudmersive’s ZDDR Whitepaper):

Malware Bazaar Date	Files Scanned	CleanResult: False (num)	CleanResult: False (%)	CleanResult: True (num)	CleanResult: True (%)	Clean File Extension Histogram
10/2/2025	332	311	93.67%	21	6.33%	.unknown(8), .js(5), .hta(1), .pdf(1), .zip(4), .svg(1), .bat(1)
10/3/2025	306	302	98.69%	4	1.31%	.js(2), .hta(1), .elf(1)
10/6/2025	477	461	96.65%	16	3.35%	.js(2), .xlsx(1), .sh(3), .ps1(1), .bat(1), .elf(1), .vbe(1), .rar(2), .unknown(2), .xls(1)
10/7/2025	412	398	96.60%	14	3.40%	.unknown(3), .sh(2), .js(2), .elf(2), .ps1(1), .rar(1), .msi(1), .py(1), .chm(1)
10/8/2025	403	390	96.77%	13	3.23%	.rar(3), .hta(2), .sh(5), .bat(2), .vbs(1)

The real-world takeaway: the API is fast enough for inline scanning and reliable enough for enterprise workflows. The metrics I have available say it definitely works.

Management & Configuration

We’ve alluded to Cloudmersive’s Management Center Portal (MCP) already in this review. This portal doubles as the control hub for API users. From the MCP, admins can generate and rotate API keys, view usage analytics for all their Cloudmersive products (including any of the non-file scanning APIs we mentioned earlier on), configure region settings, monitor call volumes, and much more.

Logging and reporting in the MCP are straightforward; it’s not fancy, but it’s practical. The interface leans functional over flashing, and I’d say that works in its favor. If you’re someone who likes elegant form with their function, you might have a few notes to leave in the suggestion box.

The Advanced Virus Scan API also exposes toggles for security sensitivity. For example, it gives customers simple dropdown menu options for determining whether to allow or disallow potentially unsafe macros or executable content within certain file types. These granular controls let teams fin-tune scanning based on their own risk tolerance, which is often missing in other “black-box” scanning APIs.

Global Data Residency

Cloudmersive provides regional endpoints around the globe, including North America, the EU, the U.K., and Asia-Pacific (including Singapore, India, and Australia). For compliance-driven organizations (e.g., those under GDPR, HIPAA, or local data-sovereignty laws), being able to choose a region is critical. While the current list covers major jurisdictions, enterprises with stricter residency demands might still find the options somewhat limited.

Here’s a full breakdown of Cloudmersive’s global server regions:

Pricing & Plans

Cloudmersive’s pricing plans follow the typical API SaaS model. They allow free developer tiers with usage caps, then metered paid plans scaling up to enterprise agreements. The enterprise tier unlocks dedicated regions, larger file size limits (which are notably small for the free-tier), and formal SLAs. Pricing transparency is decent enough, though serious adopters will likely want to discuss volume-based or managed-instance pricing directly with a Cloudmersive representative.

All in all, the trade-off is predictable. You get flexibility and easy of use on the low end, and compliance & control on the high end.

Real-World Usability

Once integrated, the API is effectively invisible to end users. The API receives a file, hands back a JSON response, and developers decide what to do next (block, quarantine, accept, etc.). Logs can be piped into SIEM tools for centralized threat monitoring. There’s no perceptible slowdown in typical web workflows, and error handling is clean through Cloudmersive’s custom API exception library. Like most SaaS/PaaS companies, the appeal is outsourced complexity with retained control.

Limitations

The API’s simplicity also serves as its primary constraint. While it offers strong file scanning, it’s not a full content-disarm or sandboxing solution. There’s no live behavioral analysis; it focuses entirely on static inspection. Additionally, integration requires developers to manage the decision logic (what happens if a scan fails? What happens when a request times out? Etc.) which isn’t what everyone considers to be “plug-and-play”.

These aren’t major drawbacks, though. They’re just the expected trade-offs of using any API-based service instead of a full appliance of proxy layer.

Conclusion

Overall, Cloudmersive’s Advanced Virus Scan API is a well-executed implementation of a simple idea: make serious, enterprise-grade file scanning accessible through an API call. It’s reliable, fast, and developer friendly, and it doesn’t attempt to be a “silver bullet” for every threat scenario (that’s part of its strength).

For teams looking to embed malware detection flexibly into different workflows, this is one of the stronger options available. Like the rest of Cloudmersive’s ecosystem, pragmatism takes a front seat to flashiness, and the result is an unglamorous workhorse that does exactly what it claims to do.