Is Download Manager (S3) safe?

Medium risk

Download Manager (S3) modifies Content-Security-Policy headers on every page and can send downloaded file hashes to VirusTotal.

The extension intercepts HTTP and HTTPS responses across all sites and rewrites Content-Security-Policy headers to append 'data:' to the img-src directive, removing that restriction site-wide. When the auto-scan option is enabled, it reads each completed download from disk, computes a SHA-256 hash, and transmits that hash to VirusTotal to check for known malware.

Part of this rating comes from analysis signals we haven't published as detailed findings yet.

Oleksandrv5.12Firefox Add-ons
46Risk
Who publishes it

Oleksandr - no other listings under this identity, 1 shared hostname

What this publisher told the store about itself, and the other listings that told it the same thing.

Shared hosts - 1 hostname

Hostnames hardcoded in this extension that few other listings call. That can mean one operator behind both, and it can equally mean a small shared vendor, so it is context rather than a conclusion. Hosts that many listings call are left out: they are services, not connections.

s3blog.org
Also called by 4 other listings

AI-generated. Findings may contain errors. Those marked Verified have been manually reviewed.

Publishers can request a review.

What it can do

Permissions this extension asks for, as declared in version 5.12. Asking for a permission is not a finding on its own - it is what the extension can do if it chooses to.

  • Read and change your data on every site you visit

    <all_urls>

  • Act on the current tab, but only after you click the extension

    activeTab

  • See the address and title of every tab you have open

    tabs

  • Show you desktop notifications

    notifications

  • Store data in your browser

    storage

  • Watch every request your browser makes

    webRequest

  • Watch, block and rewrite every request your browser makes

    webRequestBlocking

  • Start, monitor and manage your downloads

    downloads

  • Open files you have downloaded

    downloads.open

  • Read and change your full browsing history

    history

  • Add items to the right-click menu

    contextMenus

downloads.shelf

Where it sends data

Destinations our analysis observed Download Manager (S3) contacting. Sending data somewhere is not a finding on its own - an extension that syncs your settings has to talk to its own server - but it is where your data can go, and who else it goes to.

  • www.virustotal.com

    Download Manager (S3) sends data to www.virustotal.com. 8 other extensions we have analyzed send data here.

Updated 2 November 2026amo-477770