URL scan for files too large to upload. Previously, a file larger than VirusTotal's 32 MB upload limit reached a dead end. The extension can now offer to submit the file's link to VirusTotal instead, so you still get a result. This path is guarded three ways:

• Links that look like they carry a token or credential are refused and never submitted. This covers embedded credentials, signed URL parameters (for example AWS, Google Cloud, and Azure signatures), common secret query keys, and high entropy or hash like path segments.
• For other links, the query string, URL fragment, and any embedded credentials are removed before submission, so only the scheme, host, and path are sent.
• The exact link that will be sent is shown first, and a separate click is required before anything leaves your browser.

New "Don't remind me again" option. On the large file prompt you can choose to submit future large file links without being asked each time. The refusal of token bearing links always applies regardless of this setting, and you can switch the prompt back on at any time from the options page.

Redesigned UI to be a bit more seamless with the browser. The options, confirmation, and upload pages now follow your light or dark system theme and use native styling, instead of the previous fixed blue look.

Unchanged for files within the 32 MB limit. Only the file's SHA-256 hash is sent for the lookup, and the file itself is uploaded only if you choose to.

Renamed to VirusTotal Sidekick. Previously "Download Link VirusTotal Checker". Same intended use, shorter name.

Right-click no longer fetches silently. A confirmation page now opens first, showing the exact URL about to be downloaded. Nothing leaves your browser until you click Check. This avoids accidental hits on one-time download tokens, pre-signed URLs, and links with tracking side effects.

The "Upload File for Analysis" button is fixed. In the previous version, it wasn't working due to a missing message handler. Files that aren't recognized by hash can now be uploaded directly to VirusTotal from the extension.

URLs are no longer submitted to VirusTotal. Previously, when a hash wasn't found, the original URL was sent to VirusTotal's URL-scan API, where it became publicly searchable. This could expose tokens or signatures embedded in download URLs. The extension now uploads the file's bytes instead.

Other improvements

• The extension no longer requests broad "access your data for all websites" permission on install. The host permission is now optional; Firefox prompts you for each new host the first time you check a link from it.
• Uploads are sent with a fixed generic filename. Earlier drafts used the URL's last path segment, which could contain object IDs or other identifiers; that information is no longer included.
• The link you click and the final URL after any redirects are both checked against a private-network blocklist. Links that resolve to localhost, RFC1918 ranges, link-local addresses including cloud metadata endpoints, or other reserved space are rejected. URLs containing embedded credentials are also rejected.
• File downloads omit cookies, so authenticated sessions are not sent with the request.
• Recent lookup results are cached locally for 24 hours to save API quota.
• The API key field in options is now a password input, hidden by default.
• File size limit corrected from 200 MB to 32 MB (VirusTotal's public API cap).
• Streaming size check, so oversized files no longer load fully into memory before being rejected.
• All network requests now have timeouts.
• Non-HTTP(S) links (file://, data:, etc.) are rejected before any fetch.
• API key format is validated on save.
• Blocking alert() popups replaced with browser notifications.
• Network policy tightened so the extension can only talk to virustotal.com.

The background script has been rewritten in async/await, and the unused URL-scan progress page has been removed.

Small fixes and improvements.