Is "Proton ICS Auto-Importer" on Firefox Add-ons Safe to Install?

Timon · firefox · v1.0

When clicking a link that would normally download a .ics file, the extension instead opens the a page for Proton Calendar in a new tab, and adds the file to be imported. You should be logged in to proton calendar for this extension to work.

Risk Assessment

Analyzed
84.93
out of 100
HIGH

30 security findings detected across all analyzers

Firefox extension requesting 5 permissions

Severity Breakdown

0
Critical
10
High
20
Medium
0
Low
0
Info

Finding Categories

10
Malware Signatures
2
Network
17
IoC Indicators

YARA Rules Matched

5 rules(10 hits)
postinstall obfuscation postinstall network communication postinstall file download postinstall file manipulation NoUseWeakRandom

Requested Permissions

5 permissions
<all_urls>

Access and modify data on every website you visit

Dangerous
tabs
Medium
storage
Low
https://account.proton.me/u/1/calendar/import-export?ics_id=*
Low
https://account.proton.me/
Low

About This Extension

When clicking a link that would normally download a .ics file, the extension instead opens the a page for Proton Calendar in a new tab, and adds the file to be imported. You should be logged in to proton calendar for this extension to work.

Detailed Findings

13 total

YARA Rule Matches

5 rules

Indicators of Compromise

Network indicators, suspicious strings, and potential IoCs extracted during analysis

URLs
4
Domains
12
Strings
17

All Indicators · 17

Domain
detected Domain: signingca1.addons.mozilla.org

XIOC detected Domain: signingca1.addons.mozilla.org

extracted_from_files

URL
detected URL: https://account.proton.me/u/1/calendar/import-export?ics_id=*

XIOC detected URL: https://account.proton.me/u/1/calendar/import-export?ics_id=*

extracted_from_files

Hash
detected MD5 Hash: ac88a85cf6f4173553d2e18484f2dc1e

XIOC detected MD5 Hash: ac88a85cf6f4173553d2e18484f2dc1e

extracted_from_files

Domain
detected Domain: location.search

XIOC detected Domain: location.search

extracted_from_files

Domain
detected Domain: importbtn.click

XIOC detected Domain: importbtn.click

extracted_from_files

Domain
detected Domain: resp.meta.name

XIOC detected Domain: resp.meta.name

extracted_from_files

Domain
detected Domain: submitbtn.click

XIOC detected Domain: submitbtn.click

extracted_from_files

URL
detected URL: http://addons.mozilla.org/ca/crl.pem0N

XIOC detected URL: http://addons.mozilla.org/ca/crl.pem0N

extracted_from_files

URL
detected URL: https://account.proton.me/u/1/calendar/import-export?ics_id=

XIOC detected URL: https://account.proton.me/u/1/calendar/import-export?ics_id=

extracted_from_files

URL
detected URL: https://account.proton.me/

XIOC detected URL: https://account.proton.me/

extracted_from_files

Domain
detected Domain: mozilla.com

XIOC detected Domain: mozilla.com

extracted_from_files

Domain
detected Domain: addons.mozilla.org

XIOC detected Domain: addons.mozilla.org

extracted_from_files

Domain
detected Domain: content-signature.mozilla.org

XIOC detected Domain: content-signature.mozilla.org

extracted_from_files

Domain
detected Domain: tbb6d87a3a61422258ebec547752ec264.ac88a85cf6f4173553d2e18484f2dc1e.addons.mozilla.org

XIOC detected Domain: tbb6d87a3a61422258ebec547752ec264.ac88a85cf6f4173553d2e18484f2dc1e.addons.mozilla.org

extracted_from_files

Domain
detected Domain: account.proton.me

XIOC detected Domain: account.proton.me

extracted_from_files

Domain
detected Domain: date.now

XIOC detected Domain: date.now

extracted_from_files

Domain
detected Domain: message.id

XIOC detected Domain: message.id

extracted_from_files

Security Analysis Summary

Security Analysis Overview

Proton ICS Auto-Importer is a Firefox Add-ons extension published by Timon. Version 1.0 has been analyzed by the Risky Plugins security platform, receiving a risk score of 84.93/100 (HIGH risk) based on 30 security findings.

Risk Assessment

This extension presents critical security risk. Severe issues were detected, potentially including malware indicators, exposed secrets, or dangerous behaviors. Installation is strongly discouraged until these issues are addressed.

Findings Breakdown

  • High: 10 finding(s)
  • Medium: 20 finding(s)

What Was Analyzed

The security assessment covers multiple analysis categories:

  • Malware Detection: YARA rule matching against 2,400+ malware signatures
  • Secret Detection: Scanning for exposed API keys, tokens, and credentials
  • Static Analysis: Code-level security analysis for common vulnerability patterns
  • Network Analysis: Detection of suspicious network communications and endpoints
  • Obfuscation Detection: Identification of code obfuscation techniques

Developer Information

Proton ICS Auto-Importer is published by Timon on the Firefox Add-ons marketplace. The extension has approximately 3 users.

Recommendation

This extension is not recommended for installation without thorough manual review. Consider alternatives with lower risk scores, or contact the developer to address the identified security concerns.

Frequently Asked Questions