Citadel browser agent — Arno van Wouwe

Citadel is a browser agent that that enforces your IT policies and detects malware and shadow IT by analyzing and logging browser security events to syslog and Windows Event Log a privacy-respecting way. It is meant to be used by CISO and CIO to secure staff laptops, increase situational awareness, verify application of IT policy and allow Digital Forensics and Incident Response (DFIR).

Citadel can perform web filtering, limit the maximum duration of authenticated sessions, enforce your MFA policy, and help you enforce your password policy.

Citadel detects the following events in the browser:
* IP, URL or domain is blacklisted (good default blacklists provided, can be made bypassable by users)
* user is using unencrypted protocols for an application (e.g. FTP, HTTP or WS)
* user is using URL with username or password in the URL
* user has downloaded a file
* user has selected a file on the local drive (N.B. it is unknown if the file was uploaded)
* user has opened the print dialog for a page (N.B. it is unknown if the dialog was cancelled)
* the user is warned that the downloaded file is dangerous
* user has accepted downloading of a dangerous file
* user has used a password that does not conform to the password policy
* user connected using a password but without MFA, when policy requires it for this particular application
* security-related browser errors (e.g. certificate issues, detection of phishing or virus, etc.

It also reports on usage statistics of applications, allowing for detection of shadow IT and unused licences.

Events and reports are written as syslog entries with a relevant level, and can then be consumed by a SIEM or EDR. Citadel comes pre-integrated with the Wazuh, the open source XDR.