:远程管理特洛伊木马（RAT）病毒

　　远程管理特洛伊木马（RAT）病毒

　　RATs

　　The world of malicious software is often pided into two types: viral and nonviral. Viruses are little bits of code that are buried in other codes. When the “host” codes are executed, the viruses replicate themselves and may attempt to do something destructive. In this, they behave much like biological viruses.

　　Worms are a kind of computer parasite considered to be part of the viral camp because they replicate and spread from computer to computer.

　　As with viruses, a worm’s malicious act is often the very act of replication; they can overwhelm computer infrastructures by generating massive numbers of e-mails or requests for connections that servers can’t handle.

　　Worms differ from viruses, though, in that they aren’t just bits of code that exist in other files. They could be whole files——an entire Excel spreadsheet, for example. They replicate without the need for another program to be run.

　　Remote administration types are an example of another kind of nonviral malicious software, the Trojan horse, or more simply Trojan. The purpose of these programs isn’t replication, but to penetrate and control. That masquerade as one thing when in fact they are something else, usually something destructive.

　　There are a number of kinds of Trojans, including spybots, which report on the Web sites a computer user visits, and keybots or keyloggers, which record and report the user''s keystrokes in order to discover passwords and other confidential information.

　　RATs attempt to give a remote intruder administrative control of an infected computer. They work as client/server pairs. The server resides on the infected machine, while the client resides elsewhere, across the network, where it''s available to a remote intruder.

　　Using standard TCP/IP or UDP protocols, the client sends instructions to the server. The server does what it’s told to do on the infected computer.