DNS劫持是指攻击者通过篡改或控制DNS服务器，使得用户无法访问正确的网址。这种情况可能会导致用户进入错误的网站，甚至可能会被引导到恶意网站。以下是排查和修复DNS劫持的教程：
1. 确认是否为DNS劫持
- 打开浏览器，输入网址后，如果看到错误提示，如“页面无法加载”、“域名无效”等，那么很可能是DNS劫持。
- 在浏览器地址栏输入`cmd`，然后按回车键打开命令提示符。
- 输入以下命令来查看当前的DNS设置：

echo %windir%\system32\drivers\etc\hosts | findstr /i "^127.0.0.1"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^192.168."
echo %windir%\system32\drivers\etc\hosts | findstr /i "^172.16.0.0"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^169.254"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^198.51.100.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^203.0.113.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^223.6.167.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^233.105.254.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.156.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.157.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.158.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.159.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.160.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.161.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.162.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.163.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.164.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.165.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.166.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.167.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.168.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.169.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.170.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.171.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.172.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.173.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.174.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.175.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.176.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.177.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.178.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.179.*"
echo %windir%\system32\drivers/etc/hosts | findstr /i "^240.112.180.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.181.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.182.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.183.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.184.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.185.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.186.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.187.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.188.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.189.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.190.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.191.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.192.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.193.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.194.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.195.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.196.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.197.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.198.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.199.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.200.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.201.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.202.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.203.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.204.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.205.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.206.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.207.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.208.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.209.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.210.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.211.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.212.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.213.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.214.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.215.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.216.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.217.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.218.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.219.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.220.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.221.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.222.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.223.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.224.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.225.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.226.*"
echo %windir%\system32\drivers\etc\hosts | findstr /i "^240.112.227.*"
echo %windir%/n/g/r/t/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/u/v/w/x/y/z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/u/v/w/x/y/z/A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/U/V/W/X/Y/Z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/u/v/w/x/y/z/A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/U/V/W/X/Y/Z/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/u/v/w/x/y/z/A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/U/V/W/X/Y/Z)
}