• Posted by: Eng. Donya Bino
• February 08, 2026

VirusTotal Basics: How It Works

VirusTotal is a free online service (owned by Google) that scans files, URLs, domains, IP addresses, and hashes against dozens of antivirus engines and security tools. It's not your everyday antivirus, it's an aggregator that gives a crowd-sourced second opinion on whether something looks suspicious.

People use it every day to check downloads, email attachments, strange links, or even software installers before running them. It's especially handy when your local antivirus flags something oddly or gives it a clean bill but you're still unsure.

What is VirusTotal's core concept?
The original intent for VirusTotal was fairly simple; it allowed users to submit suspicious files to VirusTotal and then receive results from various different antivirus systems. As a result of these submissions, antivirus vendors received new samples of malware to study and enhance their own malware detection capabilities. This simple concept has evolved into a large public dataset of malware, which has been beneficial for both VirusTotal and antivirus vendors.

VirusTotal holds billions of files, URLs, and domains. Basic use is free; advanced features (like VirusTotal Intelligence for deep searches or private scanning) require a paid account.

How It Actually Works Step by Step
1. You Submit Something Go to virustotal.com and upload a file (up to ~650 MB), paste a URL, enter a domain/IP, or search by file hash (MD5/SHA-1/SHA-256). No account needed for basic scans, but signing in (free) lets you track history and add comments.

2. Multi-Engine Scanning VirusTotal runs your submission through over 70 antivirus scanners (e.g., Kaspersky, Bitdefender, McAfee, ESET, Malwarebytes, Microsoft Defender) plus URL/domain blocklist services. It also applies extra tools: static analysis (file metadata, strings, PE headers), behavioral signals (sandbox execution in some cases), YARA rules, and more.

3. You can view a report for your submission on the results page which includes:
a) Detection Ratio - How many of the 72 engines flagged the file as malicious? You will get a count of how many were tagged.
b) Engine Verdict + Exact Label for each engine: Eg: Trojan.Generic, PUP.Optional, etc.
c) File Details: Size, Type, Hashes, First/Last seen dates and Submission Names.
d) Extra Tab: Relations (shown as similar files); Behavior (if available, show sandbox observations); Community Comments.

4. What Happens Next
a) Your submission joins the public dataset (unless private scan).
b) New detections can retroactively update old reports.
c) If it's new malware, antivirus vendors often use it to train/update signatures.

Practical Everyday Uses
1. Checking a downloaded .exe or .zip before opening it.
2. Verifying a suspicious email link or shortened URL.
3. Looking up a file hash from your endpoint alert.
4. Spotting false positives (clean file flagged by one or two engines).
5. Researching a threat (see if others have seen it, when it first appeared).

Quick Start Tips
1. Visit virustotal.com
2. Drag a file or paste a URL/hash.
3. Wait 1–2 minutes for results.
4. Read the summary first, then drill into details if needed.

VirusTotal has saved countless people and organizations from running bad stuff. It's simple, powerful, and one of the best free tools for a quick reality check on anything digital that looks off.