Support: Reporting malware samples to the Avast Threat Lab


Avast software protects your PC via technology that proactively detects threats, such as malicious websites and files, and stops them from attacking your system. Acquiring samples of malicious code enables us to provide this protection by continuously updating our products to recognize new threats before they can infect your devices.

If you encounter a suspicious website or file, we encourage you to submit it to our Threat Lab for analysis and further action if required. This article answers common questions related to submitting malware samples to us.

How to report malware samples to the Avast Threat Lab

Who can submit files and websites?

Anyone can submit files and websites to the Avast Threat Lab for analysis. Our automated systems check all submitted files and websites for malicious or potentially unwanted activity, then take one of the following actions:


  1. If strong evidence suggests that the file or website is malicious, the file or website is blocked by our virus definition updates.
  2. If the automated system cannot determine whether the file or website is malicious, the file or website is sent to our Threat Lab analysts for manual analysis

Files and websites that require manual analysis are prioritized according to their level of severity and the number of users the file or website may harm. After manual analysis, the file or website is categorized as safe or harmful.

What types of files can I submit?

We encourage you to send us any type of file that you believe may be malicious. Be advised, we do not send replies following file submissions or evaluations.

How can I submit files?

You can submit files in the following ways:

  • Send an email to with the subject line Undetected Malware and the file attached. To submit multiple files, send them as single, compressed files (for example, in ZIP, RAR, or 7z format). For information about compressing (or zipping) files, refer to the following article:
  • Upload files to our anonymous FTP server (if the file is too large to send via email). Upload the file to the incoming/ folder then send an email to specifying the name of the uploaded file. For detailed instructions about how to use our anonymous FTP server to upload samples, refer to the following article:


How can I submit websites?

To submit a website to us for evaluation, send an email to with the subject line Undetected Malware. In the body of your message, include the full URL of the undetected website. You can also add details of the malicious behavior that you noticed when visiting the website.

To report multiple websites, send one email and include the full url and details of each.

Can I upload samples confidentially?

Avast does not collect any personal information about you when you submit files and websites to the Threat Lab. All submitted files and websites are used for research purposes only, however, uploading to the anonymous FTP server is the most private way to send us a file.

  • All Avast Software products
  • All supported operating systems

We are sorry, unfortunately this article is not available in the selected language. Would you like to continue reading the article in the current language or go to our home page in the language you have just selected?

Continue reading Go to Home page