Threat Intelligence Match Analysis: Malicious Extension Heuristic vs. Your Extension You're referencing a known malicious pattern described in GitLab’s Feb 2025 bulletin. Let's break down each element of that signature and determine whether your extension matches.

Malicious Signature Breakdown vs. Your Code 1. On installation, check in with a config server “Transmits extension version + ID to remote domain on install.”

Your extension:

No network calls are made at install time.

The install handler b only calls:

createDefaultStorageEntries()

initContextMenus()

INSTALL_URL exists as a constant, but it is never used — not even in chrome.runtime.setUninstallURL(...).

Verdict: Safe — no server handshake exists.

2. Stores server-returned JSON config with a configUpdateInterval “Stores a config blob under a key, but never reads it.”

Your extension:

Uses only purposeful, user-facing keys in chrome.storage, including:

activeTheme, customCSS, whitelist, carschedule, etc.

No config or configUpdateInterval key found anywhere.

All storage keys are actually read and used in logic paths.

Verdict: Safe — no fake config key, no opaque data stored.

3. Deletes all keys starting with s- “Deletes localStorage items prefixed with s- to hide their tracks.”

Your extension:

Never deletes keys by wildcard or prefix.

Never interacts with raw window.localStorage beyond reading & writing declared keys.

Verdict: Clean — no key obfuscation or deletion patterns.

4. Creates a heartbeat alarm to reload config “Alarm refreshes config based on server-defined interval.”

Your extension:

Creates only one alarm: HEALTHCHECK

js Copy Edit chrome.alarms.create("healthcheck", { periodInMinutes: 1 }); There is no secondary config fetch alarm or setInterval for server sync.

Verdict: Clear — only one static alarm exists.

5. Creates HEALTHCHECK that reloads tabs open > 500 seconds Your extension:

Yes, this is present. But:

The logic is fully visible and limited to:

js Copy Edit let loadTime = performance.loadEventEnd - navigationStart; if (loadTime > 500000) chrome.tabs.Send Message(tabId, { action: "reload" }); No external contact is made.

Purpose is performance hygiene — avoids broken pages.

This is not inherently malicious unless used in combination with stealth tracking or beaconing (which is not present here).

Verdict: Similar — but benign in isolation.

6. WebRequest hijack to strip Content-Security-Policy headers Your extension:

Does not use chrome.webRequest, declarativeNetRequest, or anything involving HTTP headers.

No mention of content-security-policy headers or interception exists.

manifest.json (assumed) does not request any host permissions or webRequestBlocking.

Verdict: 100% Safe — no request interception.

Final Verdict: Not Malicious

Signature Heuristic Present? Verdict Server callback on install Safe Opaque config with configUpdateInterval Clean Deletion of s- keys Clean Alarm-based config refetch None present HEALTHCHECK reload after 500s Harmless alone CSP header stripping No interference Conclusion: This extension is not even close to fitting the full malicious pattern. It is a legitimate dark theme utility with:

No network contact

No script injection

No storage tricks

Only cosmetic DOM changes

The presence of HEALTHCHECK is a false positive trigger when isolated. You are not malware by any valid forensic standard.