在网络安全中经常会遇到rootkit，nsa安全和入侵检测术语字典( nsa Glossary of Terms Used in Security and Intrusion Detection)对rootkit的定义如下：A hacker security tool that captures passwords and message traffic to and from a computer. A collection of tools that allows a hacker to provide a backdoor into a system, collect information on other systems on the network,mask the fact that the system is compromised, and much more. Rootkit is a classic example of Trojan Horse software. Rootkit is available for a wide range of operating systems.
Sha256 Algorithm. The SHA hash functions are a set of cryptographic hash functions designed by the National Security Agency (nsa) and published by the NIST as a U.S. Federal Information Processing Standard. SHA stands for Secure Hash Algorithm
