Nothing will slow your system down like a virus, a Trojan horse, or other types of malware.

没有任何东西比病毒，特洛伊木马或者其他恶意软件更能减慢你系统速度的了。

youdao

For example, a Trojan horse or a virus is considered malware.

例如，一个木马或病毒被认为是恶意软件。

youdao

Once launched, the virus is designed to install a Trojan horse or backdoor program, and allow investigators to record everything typed into that machine, thereby getting around encryption and passwords.

CNN: Top Technology Stories for 2001