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12Versions
1Code reviewed

No malware found

In code review (v0.4.53)

Our reviewer read version 0.4.53 — the most recent version we have reviewed — and found no malicious behaviour. The version shown here has not been individually reviewed yet.

What our analysis found

MasteryConnect LockDown Browser, used by 2,000,000 people, showed no malicious code in Extension Auditor's review. Its permissions mean it can read and change data on all websites, can inject scripts into pages and can observe network requests. It comes from a publisher with 14 extensions and was last updated in September 2026.

The extension is a legitimate lockdown browser for exams by Respondus Inc., a known educational software publisher. The broad permissions (webRequest, cookies, history, etc.) are necessary for its stated purpose of preventing cheating. All network communication observed goes to Respondus's own servers (), matching the first-party privacy policy. The CWS-disclosed data collection of personally identifiable information covers the data flows. The bundled manifest includes additional web_accessible_resources not in the published summary, but these are innocuous and related to new features. No evidence of malicious behavior or unauthorized data exfiltration was found in the reviewed code.

MasteryConnect LockDown Browser

MasteryConnect LockDown Browser Chrome extension security report

ID: nkkighcdodpjcdenompholalclpaobff

Supported Languages

🇺🇸English
🇫🇷French
🇩🇪German
🇮🇹Italian
🇪🇸Spanish

Extension Info & Metadata

Status
Active
Version
0.4.91
Size
4.60 MB
Rating
1.5/5
Reviews
39
Users
2,000,000
Type
Extension
Updated
Sep 23, 2026
Category
Workflow & planning
Price
Free
Featured
No
Visibility
Listed
Mature
No
By Google
No
Trusted
No
Download CRX
Chrome Web Store
Report Issue
This publisherTrack record
14extensions
1 no longer listed
Scanned by Extension Auditor — Low RiskDevelopers: embed this badge to link to this report.

Publisher Contextual Analysis

Author
Respondus Inc
Privacy
Privacy Policy
Country
US
MX records exist
Yes
Domain exists
Yes
Is disposable
No
Is role-based
Yes
Mailbox exists
Yes
Address
8201 164th Ave NE suite 200 Redmond, WA 98062 US
Website
Visit
Extensions
14
Active
12
Obsolete
1
Listed
1
Unlisted
13
Users
30,240,000

Email Change History

1 change
Feb 14, 2025

Screenshots & videos

Screenshot 1

Install growth

Item
Type
Severity
Description
webRequest
Permission
Critical
This permission enables the extension to monitor and analyze all web requests made by the browser. Rated Critical because it can observe all network traffic including sensitive data, track browsing behavior, and gather authentication tokens.
scripting
Permission
Critical
This permission allows injection and execution of JavaScript on any webpage. Rated Critical because it can modify page content, steal sensitive data, and inject malicious code into any site the extension has access to.
declarativeNetRequestWithHostAccess
Permission
Critical
This permission combines network request modification with host permissions. Rated Critical because it can modify requests for specific domains, potentially targeting sensitive websites with precise attack rules.
http://*/*
Host
Critical
Broad host access — the extension can read/modify content on every website.
https://*/*
Host
Critical
Broad host access — the extension can read/modify content on every website.
<all_urls>
Host
Critical
Broad host access — the extension can read/modify content on every website.
Dangerous Permission Combination: scripting,<all_urls>,webRequest
Risk Factor
Critical
Enables sophisticated data theft through script injection and traffic monitoring
Dangerous Permission Combination: scripting,<all_urls>,cookies
Risk Factor
Critical
Enables sophisticated data theft through script injection and traffic monitoring
history
Permission
High
This permission grants access to your complete browsing history. Rated High because it can track all visited websites, reveal sensitive browsing patterns, and expose private information.
cookies
Permission
High
This permission provides full access to read and modify browser cookies. Rated High because it can steal session tokens, modify authentication cookies, and compromise accounts across websites.
webNavigation
Permission
High
This permission enables monitoring of all browser navigation events and transitions. Rated High because it can track every page visit, navigation method, and browsing pattern, potentially exposing sensitive browsing behavior and user activities.
contentSettings
Permission
High
This permission allows modification of website-specific content settings. Rated High because it can disable security features like JavaScript restrictions, mixed content blocking, and cookie controls for specific sites.
browsingData
Permission
High
This permission clears browsing data, history, and redis. Rated High because it can destroy evidence of malicious activity, clear security logs, and modify browser state.
clipboardRead
Permission
High
This permission allows reading clipboard content. Rated High because it can steal copied passwords, sensitive data, and monitor all content copied to clipboard.
clipboardWrite
Permission
High
This permission allows modification of clipboard content. Rated High because it can inject malicious content into the clipboard, modify copied passwords, and manipulate copied data.
Dangerous Permission Combination: scripting,cookies,webRequest
Risk Factor
High
Enables extensions to interact with scripts, modify files and downloads, and alter browsing history and bookmarks, potentially affecting data integrity and user control.
Broad Host Permissions
Risk Factor
High
This extension has broad host permissions allowing it to access many or all websites.
Broad Content Script Access
Risk Factor
High
This extension can inject scripts into any website.
storage
Permission
Medium
This permission allows storing data locally in the browser. Rated Medium because it can persist sensitive user data, track user activities over time, and potentially store malicious payloads.
tabs
Permission
Medium
This permission enables tab management and monitoring. Rated Medium because it can track open tabs, access tab metadata, and monitor user browsing patterns.
activeTab
Permission
Medium
This permission grants temporary access to the current tab. Rated Medium because it can access current page content when invoked, though limited to user-initiated actions.
management
Permission
Medium
This permission manages other installed extensions. Rated Medium because it can enable/disable other extensions and modify their settings, with changes being visible to users.
wallpaper
Permission
Medium
This permission manages ChromeOS wallpaper settings. Rated Medium because it can modify system appearance and potentially access wallpaper images.
system.display
Permission
Low
This permission reads display configuration. Rated Low because it only accesses screen properties without content access.

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About this extension

LockDown Browser is a custom browser that locks down the exam environment within specific learning and assessment systems

Read the publisher’s full description

Mastery Connect LockDown Browser is a custom browser extension that protects the integrity of the exam process by preventing cheating by students while the exam is in session.

User reviews

Extension files

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URLs
42
IPv4
2

URLs

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No URLs found
No IP addresses found

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Version
Size
Verdict
Findings
Permhash
0.4.91
Latest
4.60 MBNot scanned—
4bd4505c62fbb3ed678f3b82df3953ee7ad87f92465071c07922636859230a05
0.4.85
4.53 MBNot scanned—
4bd4505c62fbb3ed678f3b82df3953ee7ad87f92465071c07922636859230a05
0.4.53
4.46 MBNo malware found0
4bd4505c62fbb3ed678f3b82df3953ee7ad87f92465071c07922636859230a05
0.4.48
4.36 MBNot scanned—
4bd4505c62fbb3ed678f3b82df3953ee7ad87f92465071c07922636859230a05
0.4.41
4.36 MBNot scanned—
4bd4505c62fbb3ed678f3b82df3953ee7ad87f92465071c07922636859230a05
0.4.34
4.39 MBNot scanned—
d07b26a6c27bcb4c80a27e114c979f596655d454bb7b79aa27dbedaf239ebb89
0.4.00.28
4.29 MBNot scanned—
95a9cf27891490363ee66e6e8088d40faba6da60f7c9fe8678f494fa4204e6f6
0.3.00.046
1.09 MBNot scanned—
676055d25005af1be2a92327f7797f0e4f4f1f4043f18db7233b51043bf5b34a
0.3.00.045
1.09 MBNot scanned—
e8f7f59276a343406f85d046a5620b5091fb4d725c252904aeb9f83162aa6f09
0.3.00.030
1.14 MBNot scanned—
4ba98f0798625698ed68d8168ff38c70fd827ec9e6febe0d97f4cf8b4085b3d2
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Code Diff

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0 changed files detected

No comparable text files found between these versions.

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