SECURITY REPORT · EXTENSHI SCAN
Niconico Downloader
Firefox extension·by Nekoziroo
0
/ 100 SAFETY SCORE
EXCELLENT
Looks clean. No meaningful risks detected in this scan.
Automated analysis of publicly available code — not a professional security audit. It may produce false positives and does not prove an extension is unsafe or safe. Treat it as one signal among many. Disclaimer · Report an issue
How it ranks
Niconico Downloader's safety score vs every other extension we've scanned
Globally
98.84%of extensions carry more risk
Riskier ←→ Safer
Ranked across every extension we scan
In its category
88.84%of its category extensions carry more risk
Riskier ←→ Safer
Ranked within its category
Findings
1
median 38Lower is safer
Risky permissions
2
median 1Critical + high perms
Total permissions
6
median 4All declared perms
Critical findings
0
median 2Severity = Critical
Findings breakdown
Automated security signal · 1 distinct issue across 6 severities
1
distinct issues
detected
detected
Scanners reported 2 raw occurrences; repeats of the same issue at the same location are merged here. The list below shows every occurrence.
Critical00%
High00%
Needs Review00%
Medium00%
Low1100%
Info00%
Permissions requested
2 risky permissions of 6 total
2 high-risk permissions require attention
This extension requests 6 permissions in total. 2 of them grant broad capabilities that are worth a careful look.
High
Manage downloads
Can initiate downloads and access your download history
High
View open tabs
Can see URLs and titles of all open tabs
Medium
Access current tab
Can temporarily access the content of the active tab when you click the extension
Medium
Store local data
Can save data locally in the browser for persistence
Info
http://ext.nicovideo.jp/api/getthumbinfo/*
No additional information available.
Info
*://www.nicovideo.jp/watch/*
No additional information available.
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Scan performed by extenshi.io · Jul 25, 2026· partial run (some scanners failed)
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