As a highly dangerous and covert remote control tool, trojan horse is commonly used techniques on network intrusion.

木马作为一种危害性大、隐蔽性高的远程控制工具，是目前比较常用的网络入侵技术。

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To open a door fitted with the latest U.S. government-certified lock from high-end Swiss lock manufacturer Kaba, an employee must both enter a code up to eight digits long, then swipe a unique identity card coded to comply with a new standard that requires an extra layer of security, one designed to track individual staffers and make covert intrusion harder than ever.

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