For Hotspot Shield's IKEv2 mode, SNI-only blocking failed because logged SNI hits corresponded to the VPN's own domain/CDN traffic while tunnel-negotiation domains (journalissue.us, middle-island.us) went unlogged; switching the rule to match DNS query name (qname) for those specific domains successfully blocked the connection.
单独下策略 阻断dns 其filter使用的qname 为hotspot_shield_vpn_20230602中使用的dns qname...journalissue.us及 middle-island.us 一直在尝试获取IP 但均为获取到IP。安全日志有dns 阻断日志,此时节点无法连接。
Defense implications
- TSG switched detection layers (SNI to DNS-qname) specifically because SNI matching failed -- tools should validate that internal-only negotiation domains (never shown in any UI/cert) aren't distinctively named, since operators tend to under-rotate exactly these artifacts.
Related findings
Geedge's TSG self-check test suite (run against firewall version v23.07.18-591aed7) enumerates the product's full interference capability set: SSL bypass/intercept (including handling of expired, self-signed, and untrusted-root certificates), HTTP/SSL proxy actions (redirect, block, replace, hijack, insert), three distinct firewall deny modes (silent drop, TCP RST, blockpage), and DNS deny modes (silent drop, A-record redirect, AAAA-record redirect, including TTL-range variants).
As of TSG v23.07, FQDN matching supports left-anchored prefix/wildcard matching (e.g. 'voice-group-80x-api.*'), added specifically so a Fujian domestic deployment could detect domains with a fixed subdomain prefix but rotating remainder. Earlier versions only supported exact FQDN match.
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.
Raw structured DNS event logs (dated 2021-08-23) captured from what appears to be a GFW-adjacent DNS monitoring/injection pipeline use a schema purpose-built for DNS response forgery ('CHEAT_TYPE', 'CHEAT_RCODE', 'CHEAT_STRATEGY', 'CHEAT_RR', 'INJECTED_PKT_FILE' fields) alongside per-query geolocation; sampled records show lookups for facebook.com and tiktokv.com originating from residential China Telecom/Unicom/Mobile subscriber IPs in Guangdong, Zhejiang, Anhui and other provinces, resolving against both domestic and foreign (8.8.8.8, OpenDNS) resolvers.
A 2023 MESA Lab monthly report describes the 'TF' project's active-defense work: test cases for serial ('串联') HTTP hijack/tamper and parallel ('并联') DNS race-injection ('DNS抢答'), performance tuning that scaled active-defense capacity from 3 to 5 units, converting two existing TSG boxes to active-defense mode, and rewriting the active-defense flow-control logic to no longer depend on sapp.
TSG automatically generates recurring weekly "SNI Report of Overseas APP" and companion "Server IP and Location of Overseas APP" reports at what is almost certainly a China-national (not export-customer) scale — single weekly runs process from ~5.7 trillion to over 135 billion rows and up to ~775TB/week — breaking down QUIC.SNI/SSL.SNI/HTTP.Host traffic per named blocked-in-China platform (YouTube, Facebook, Google, Twitter, Instagram, Telegram, WhatsApp, Netflix, BBC, Viber, Line, Snapchat, Gmail, HBO, and more), down to individual CDN edge hostnames (e.g. specific scontent-*.fbcdn.net and rr*---sn-*.googlevideo.com nodes ranked by bytes). The report series recurs weekly from at least Feb 2023 through Mar 2024.