An undocumented way of accessing a system or software, usually used by hackers to bypass security.
一种未记录的访问系统或软件的方式，通常由黑客用来绕过安全防护。 (Yi zhong wei jilu de fangwen xitong huo ruanjian de fangshi, tongchang you heike yonglai raoguo anquan fanghu.)
"The attacker installed a backdoor to access the system at any time without being detected."
"攻击者安装了一个后门，以便在任何时候都能访问系统，而不被发现。" (Gongji zhe anzhuang le yi ge **houmen**, yi bian zai renhe shihou dou neng fangwen xitong, er bu bei faxian.)
to feel very happy
To plan a way to achieve something.
a spoken mistake; saying something unintentionally
a state of political hostility without open warfare
used when you meet someone after a long time
to suffer from a bad experience or mistake
