FastSaveSecurity Analysis

Chromev3.8.3MV3February 18, 2026 at 11:54 AM
Potentially unsafe

This extension shows concerning patterns that may indicate risky behavior. Proceed with caution.

6.6HIGH
6.6 HIGHRaw: 8.3

This extension shows significant risk signals. Review the findings below carefully before installing or continuing to use it.

Based on 11 permissions including high-risk ones, 36 code findings, 3 dangerous combinations.

Trust Signals(4.0/10)

Users
100K
Rating
4.9(335 reviews)

Dangerous Combinations(3)

CRITICALBulk cookie access + external network

Extension uses chrome.cookies.getAll for bulk cookie access and sends data to external servers — high risk of session token theft.

cookies+chrome.cookies.getAll + external network
MEDIUMTab tracking API + external communication

Extension uses tab tracking APIs (onUpdated/query) and communicates with external servers — potential browsing surveillance.

tabs+tabs API usage + external network
CRITICALNetwork interception + external communication

Extension intercepts network traffic and sends data externally — potential man-in-the-middle behavior.

webRequest/webRequestBlocking+external network request
Permissions
8.5/10
Code
7.6/10
Combinations
10.0/10
Manifest/CSP
7.0/10

Permissions(11 analyzed)

Code Findings(18 patterns, 36 total)

Content Security Policy

CSP Present(1 issue)
LOW
object-srcobject-src not restricted

object-src is not set to 'none'. Plugins like Flash can be embedded, which may allow code execution.

Manifest Analysis(4 findings)

Resolved from __MSG_* i18n placeholders:

Name: FastSave

Description: Repost Instagram stories, save video, photo and Reels. Browse Instagram site like a mobile app.

HIGH
web_accessible_resourcesJS files exposed to web pages

JavaScript files are accessible to ALL websites. Any page can load and interact with these scripts, enabling web→extension attacks.

MEDIUM
web_accessible_resources.matchesOverly broad match patterns

Web-accessible resources use <all_urls> or wildcard patterns, exposing resources to every website.

HIGH
content_scriptsAggressive content script injection

Content script runs at document_start in ALL frames on ALL URLs. This gives the extension deep access to every page load, including iframes.

HIGH
content_scriptsAggressive content script injection

Content script runs at document_start in ALL frames on ALL URLs. This gives the extension deep access to every page load, including iframes.

External Domains(5)

*.instagram.comreact.devspector.netstuk.github.iowww.instagram.com

Indicators of Compromise

17 indicators of compromise found

File Statistics

86
Total Files
14
JS Files
1.7 MB
Total Size

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