Science & Tech · Cybersecurity · 3 hrs ago
Online malware scans can expose sensitive files to third parties
Online malware scanning services let people submit files or web links to check for threats.
Some services share submitted files with security firms or researchers to help detect new malware and improve antivirus tools.
This can expose personal details or company secrets if they are included in a file.
VirusTotal, MetaDefender Cloud and Jotti's Malware Scan say they may share files under certain conditions, though access rules differ by service.
In one case, more than 1,700 documents with sensitive company information were submitted for public analysis on ANY.RUN, after some files were incorrectly flagged as malicious by Microsoft security software.
Experts advise keeping sensitive files off public scanning sites and using antivirus software on the device or an organization’s internal security system instead.
If an online scan is necessary, users should check whether private scanning is available and who can access submitted files; companies and public agencies are also advised to set rules and train staff.
Some online malware-scanning services may share submitted files with security companies or researchers.
Files containing personal information or business secrets could therefore be exposed when uploaded for a scan.
Users should check a file’s contents and the service’s sharing policy before submitting it.
Security experts recommend using device-based antivirus software or internal company systems for sensitive files.
If an external scan is necessary, users should check whether the service offers private scanning and who can access submitted files.
- Who
- Users of online malware-scanning services, including individuals and organisations.
- What
- Some services may share submitted files with security companies or researchers, creating a risk that sensitive information could be exposed.
- When
- Yonhap published the report on November 3, 2026.
- Where
- Online malware-analysis services that receive files on external servers.
- Why
- Some services share files to help detect new malware and improve antivirus detection.
This story does not have two clearly opposing sides.
More than 1,700 documents containing sensitive corporate information were reportedly submitted for public analysis on ANY.RUN.
ANY.RUN switched the related analysis work to private.
Yonhap reported on the risks of submitting sensitive files to online malware-scanning services.
- VirusTotal
- May provide submitted files and webpages to security companies or customers with paid-service access.
- MetaDefender Cloud
- May share files submitted through general scans with antivirus companies or approved security researchers.
- Jotti's Malware Scan
- Says it shares submitted files with antivirus companies to improve detection accuracy.
- ANY.RUN
- More than 1,700 sensitive corporate documents were reportedly submitted for public analysis in April 2025.
- Safer checks
- Experts recommend device-based antivirus software or internal security systems for sensitive files.
What people are saying
Online malware analysis services are a useful means of detecting cyber threats, but checking whether a file is infected with malware and protecting the confidentiality of information in the file are separate issues.
It is important to check the sensitivity of the information and the service’s sharing policy before uploading a file so that an attempt to check security does not become a new route for information exposure.