Geedge runs an ongoing, largely manual weekly signature-extraction program against commercial VPN apps (LetsVPN, Betternet, VPNLITE, and a ~80-app batch), combining server-IP lists, FQDN patterns, and payload/SNI/Host/User-Agent signatures, tested for blocking efficacy and false-positive rate before rollout. VPNLITE was fingerprinted via TCP direct-connect on ports 18000/3320/8099 plus TLS to randomized .xyz/.info subdomains on Cloudflare ranges (104.21.0.0/16, 172.67.0.0/16).
TCP直连方式节点端口范围为[18000, 3320, 8099]...实际承载ip位于地址段[104.21.0.0/16, 172.67.0.0/16]中，且均为cloudfare云服务节点。
Defense implications
- IP/FQDN-pattern blocking requires continuous weekly human effort against apps that rotate infrastructure -- LetsVPN/Betternet tracking shows hundreds of new IPs most weeks, implying rotation imposes real recurring cost on this defense class.
- Randomized subdomains behind a narrow, well-known CDN IP range are themselves fingerprintable once noticed -- fronting through large, shared, non-attributable CDN ranges is more resistant than a provider-specific narrow range.
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/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.
The GitLab group itself is named "K18_NTCS_WEB" (K18 = Kazakhstan), and its "nfs" web app implements per-protocol keyword-filter configuration classes (App/FTP/Mail/P2P/SSL keyword configs), an OpenVPN IP-list config, RADIUS-based logging/reporting entities, MAAT rule-sync beans, and an explicit "IP spoofing" business feature with its own "PXY仿冒地址池" (proxy spoofed-address pool) and dedicated policy-log support -- the single strongest piece of evidence in this batch tying named keyword-filtering plus IP-spoofing capabilities directly to the Kazakhstan deployment.
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.
Geedge fingerprinted several V2Ray-based VPN apps by their fixed API/bootstrap domains rather than protocol characteristics — blocking "V2 Pro" via pro.mucacherry.org, "V2 VPN" via v2.mucacherry.org, and "V2Net VPN" via api.v2net.live plus 5 rotating free-node domains (free1-5.v2n3t2.online / v2n3t.online) the app uses to fetch node lists.