TSG/CM ships with pre-built, first-class 'Learning Object' entries specifically for Freegate (Object ID 18) and Psiphon3 (Object ID 19), plus a generic 'Top Server IP' object (ID 20) -- default product features, not customer-commissioned custom signatures. The Psiphon3 object auto-learns and dynamically updates a live blocklist that reached roughly 70,000 IPs at one deployment before a database issue temporarily dropped it to ~50,000.
Freegate Client IP（Object ID：18）...Psiphon3 Client IP（Object ID：19）...Top Server IP（Object ID：20）
Defense implications
- Freegate and Psiphon3 are explicitly named, first-class blocking targets shipped by default -- any tool this well-known should assume out-of-the-box detection wherever TSG is deployed, not just custom signature work.
- The auto-learning IP blocklist reaching tens of thousands of entries confirms large-scale dynamic IP churn is already handled operationally; static-IP-list tools at this scale should not assume obscurity.
Related findings
A crash/perf bug report reveals Geedge's MAAT rule engine (libmaatframe.so, using Intel Hyperscan for literal/regex matching) running with 545,441 FQDN blocking rules and 404,141 IP address blocking rules loaded in a single instance as of 2024; loading 500,000 new FQDN rules via the full Hyperscan path took ~95 minutes, addressed by an automatic fallback to a second engine ("Rulescan") above 50,000 rules.
TSG maintains a traffic-volume-ranked "Top SNI" / "Top Server IP" allowlist (Galaxy component, learned from live traffic, capped at top ~2000 SNIs / ~40000 server IPs per Nacos config) that is checked before a VPN/circumvention-tool deny policy (including a Psiphon3-specific policy) is enforced. Confirmed empirically: Psiphon3 client traffic whose destination SNI was in the Top SNI list passed through undenied, while traffic to the same client IPs with an SNI not yet in the list was blocked. A 2022-06 incident over-blocked TikTok/BBC/CNN/NYTimes because their SNIs were not yet in the learned allowlist at the time.
Geedge extracted and analyzed Betternet VPN's underlying protocols (WireGuard, a proprietary "Hydra" protocol using spoofed-domain TLS 1.2, and IKEv2), and found the Hydra protocol could be "completely blocked" via JA3 TLS fingerprinting; IKEv2 was blocked via UDP port 500/4500 policy, and thousands of VPN server IPs were extracted as a supplementary IP blocklist.
Geedge extracted ProtonVPN server IPs using the app's own debug-log output to find its server-list API endpoint, directly querying it to harvest ~5,800 server IPs, then used automated repeated connection cycling to extract ~200 additional rotating IPs after the initial list was blocked; the app was subsequently reported fully blocked on Android, iOS, and Windows.
For a domestic Fujian deployment, Geedge validated SNI-wildcard blocking (*.sohucs.com, *.sns.sohu.com) as technically effective against a specific Chinese social app ('Huyou'), but rejected it for production because the domain is shared with a third-party SDK platform and would cause false-positive blocking of unrelated services -- falling back to destination server-IP blocking, deployed inline via TCP RST injection.
Geedge runs an ongoing, weekly-cadence feature-extraction and blocking program against a customer-curated list of at least 282 named commercial VPN/circumvention apps (including Fly VPN, Secure VPN, NotVPN, letsVPN, VPN Hero, BeastVPN, Cafe VPN, Blockless VPN, BlackVPN, FinchVPN, Cisco Secure Client/ocserv, DelightVPN, NordVPN), plus separate systematic testing of 400+ non-VPN apps. The methodology extracts destination server-IP lists (hundreds to thousands of IPs per app) and app-specific FQDNs, tests each in staging for false positives before deploying, and for at least one target stood up their own clone of the target VPN server software to capture and analyze its real protocol handshake.