IP hijacking is the act of an attacker illegally tampering with the server IP or DNS resolution path and directing traffic to malicious nodes. The hazards mainly include data leakage, service interruption and related legal risks. If an individual user encounters IP hijacking, how should it be solved? The following will share with you the removal process and the method of building a protection system.

1. Hijacking type identification and emergency response

You need to understand the hijacking type in advance. DNS hijacking means that when a user accesses a domain name, he is redirected to other websites, or the browser will prompt "the network is hijacked by hackers." Check the resolution result through `nslookup domain name`. If the returned IP does not match the authoritative record, the hijacking is confirmed.

Signs of server IP hijacking are that the server cannot be accessed through the original IP, the traffic surges abnormally but the business requests decrease, or unknown administrator logins appear in the security log. The emergency operation is to immediately isolate the infected server and cut off the network connection to prevent lateral penetration. Enable the backup node to take over the service and give priority to restoring business continuity.

II. Technical path to remove DNS hijacking

Clear the polluted cache and clean up the caches at all levels in layers. The local system is Windows. Execute:

ipconfig /flushdns

Linux uses:

sudo systemdresolve flushcaches

macOS runs:

sudo killall HUP mDNSResponder.

The browser is Chrome/Firefox. DNS cache and cookies need to be cleared. The router needs to restart the device or log in to the management interface to manually clear the DNS records.

Replace the authoritative DNS service. Change the local DNS server address to a public trusted service, such as Google DNS (8.8.8.8) and Cloudflare (1.1.1.1). The enterprise network needs to prohibit access requests to external malicious DNS (such as known hijacked IP) in the firewall policy.

Deploy encrypted DNS protocol. DoH (DNS over HTTPS) encrypts queries through port 443, and Chrome can be enabled in `chrome://flags`. DoT (DNS over TLS) routers are globally configured with port 853 encryption to block middleman monitoring.

Hosts file is forced to resolve. For key domain names (such as official website, API), execute `dig @1.1.1.1 domain name` through overseas VPS to obtain the correct IP, and edit the Hosts file to add records:

192.0.2.1 example.com (Windows path: `C:\Windows\System32\drivers\etc\hosts`).

3. Deep processing of server IP hijacking

Source tracing and vulnerability repair. Analyze server logs to locate intrusion points (such as brute force cracking records, abnormal processes). Immediately patch related vulnerabilities (such as unauthorized RDP access, Apache vulnerability CVE202144228), and update all patches.

Reset the system and restore data, reinstall the operating system, format the disk to clear the persistent backdoor. Restore data from offline backup to ensure that the backup has not been tampered with (verify the hash value).

DNSSEC is forced to verify. Enable DNSSEC at the domain name registrar, generate key pairs (KSK/ZSK) and sign zone files. The authoritative DNS server is configured with `dnssecenable yes` to ensure that the resolution response carries a digital signature to resist forged IP.

The network layer strengthens the firewall rule restrictions, only opens necessary ports (such as 443/22), and refuses access to unconventional protocols. Enable BGP route monitoring to warn of illegal route announcements in real time.

IV. Construction of a comprehensive defense system

In terms of infrastructure protection, the server should install EDR endpoint protection, configure file integrity monitoring (FIM), disable vulnerable protocols such as WPS and UPnP on the router, and update the firmware monthly.

The continuous monitoring mechanism should first deploy the SIEM system to correlate and analyze DNS logs, NetFlow traffic and server events. Set up automated alarms to trigger work orders when the resolved IP deviates from the whitelist or the TTL is abnormal. In the business-level disaster recovery design, multiple CDN redundancy can be automatically switched if any node is hijacked. Distributed authoritative DNS: self-built resolver clusters to reduce external dependence.

V. Legal compliance and industry collaboration

When an enterprise encounters large-scale hijacking, it is necessary to submit technical evidence (including traffic capture pcap files and log timestamps) to the Internet Information Office and ICANN. Join the "Anti-Hijacking Alliance" to share threat intelligence (such as malicious IP databases). At the same time, conduct regular penetration tests and red-blue confrontations to verify the effectiveness of protection. In short, IP hijacking should follow the four-step rule of isolation, removal, reinforcement, and verification. In the short term, it depends on DNS reset and system restoration, and in the long term, it is necessary to build encrypted transmission, active monitoring, and infrastructure redundancy. Technology needs to improve team awareness and join industry collaboration mechanisms.