Every file you download from the internet is a potential risk. Executable programs, PDF documents, Office files, ZIP archives, and even image files can carry malware — and your installed antivirus might not catch everything. Scanning a file with multiple engines before opening it takes 30 seconds and can prevent a serious infection.
Here's how to scan any file for viruses online, for free, before you open it.
Why You Should Scan Files Before Opening Them
No single antivirus engine catches 100% of threats. New malware variants appear daily, and it takes time for individual antivirus vendors to update their databases. Scanning a file against 95+ antivirus engines simultaneously dramatically increases the chances of catching something that your installed antivirus would miss.
The files most commonly used to deliver malware in 2026:
- Executable files (.exe, .msi, .bat, .ps1) — the most direct delivery method
- Office documents (.doc, .docx, .xls, .xlsm) — with malicious macros embedded
- PDF files — can contain JavaScript exploits or malicious links
- ZIP and RAR archives — often used to bypass email filters
- APK files — Android apps downloaded outside the Play Store
- Scripts (.js, .vbs, .py) — especially dangerous if double-clicked
How to Scan a File for Viruses Online (Step by Step)
Go to ShieldScan's File Scanner
Visit shieldscann.io/file-scanner or open the main app and click the File tab. No installation or account required to get started.
Upload your file
Click the upload area or drag and drop the file directly. Supported file size is up to 32MB. Any file type is accepted — EXE, PDF, Word, ZIP, APK, scripts, and more.
Click Scan
Hit the Scan button. ShieldScan sends the file to VirusTotal's network of 95+ antivirus engines simultaneously. The scan typically completes in 10–30 seconds.
Read the results
You'll see a 0–100 Risk Score and a verdict. If any engines flagged the file, you'll see exactly which ones and what threat category they detected. A clean result means no known threats were found across all 95+ engines.
Supported File Types
ShieldScan accepts any file type up to 32MB, including:
What the Scan Results Mean
Risk Score 0–9 (Safe)
No antivirus engines flagged the file. It's safe to open. This is the result you want to see.
Risk Score 10–34 (Low)
One or two engines flagged the file with low-confidence detections. This may be a false positive — especially for software that modifies system files or uses code obfuscation. Check which engines flagged it and what they detected before deciding.
Risk Score 35–69 (Medium)
Several engines flagged the file. Exercise caution. The file may be malicious or potentially unwanted (adware, spyware). Consider not opening it unless you have a strong reason to trust the source.
Risk Score 70–100 (High / Critical)
Multiple engines flagged the file as malicious. Do not open it. Delete it immediately and scan your system with your installed antivirus if you already interacted with it.
When to Be Extra Cautious
Always scan before opening when:
- The file came from an email attachment you weren't expecting
- You downloaded it from a file-sharing site, torrent, or unofficial source
- A contact sent it via messaging app (WhatsApp, Telegram, Discord) without context
- The file extension doesn't match what you expected (invoice.pdf.exe is actually an executable)
- The file was "cracked" or "patched" software downloaded to bypass licensing
Limitations of Online File Scanners
Online file scanners are powerful but not perfect. Keep these limitations in mind:
- New malware may not be in any database yet (zero-day threats)
- Encrypted archives with passwords can't be scanned until extracted
- False positives occur occasionally — especially for custom or self-compiled software
- File size limits — files over 32MB need to be scanned with local antivirus software
Scanning Files on a Mac
Mac users face malware too — particularly adware, spyware, and targeted attacks on macOS. ShieldScan works fully on Mac via any browser. Simply visit the site, upload your file, and scan. No installation needed, no macOS compatibility issues.
Scanning APK Files (Android Apps)
If you're installing Android apps from outside the Google Play Store (sideloading), always scan the APK first. Malicious APK files can steal contacts, messages, banking credentials, and location data. ShieldScan handles APK files up to 32MB — just upload and scan before installing.