description-logo Description

This indicates an attempt to access Psiphon.
Psiphon is a censorship circumvention tool from Psiphon Inc. It uses various communication and encrypted protocols like QUIC, SSH, SSL, HTTP Proxy to tunnel traffics through a firewall. It is designed to support users with heavy censorship in their country. The concept was developed by Citizen Lab. It is one of the most popular proxy app today.
Note: Psiphon requires setting the QUIC signature and proxy category to block.
SSL deep inspection is required for some of the versions to get 100% block rate. When deep inspection is enabled, please turn off "Replacement Messages for HTTP-based Applications" in application sensor if you are on FortiOS 5.4 or 5.6.

affected-products-logoAffected Products

Psiphon

Impact logoImpact

Firewall policy avoidance

Technology

Browser-Based, Network-Protocol, Client-Server, Peer-to-Peer, Cloud-Based, Mobile-Device

Behavior

  • Evasive
  • Tunneling

Default Ports

  • TCP/1-1024
  • UDP/1-1024

Version Updates

Date Version Detail
2024-01-30 26.724 Sig Added
2023-12-12 26.693 Sig Added
2023-12-07 26.691 Sig Added
2023-11-30 26.687 Sig Added
2023-11-28 26.685 Modified
2023-08-22 25.625 Modified
2023-07-18 25.604 Sig Added
2023-07-18 25.602 Sig Added
2023-06-22 24.587 Sig Added
2022-11-29 22.448 Modified