This often happens via attachments sent in email or shared USB drives.

通常会在附件或U盘中出现。

We'll start with viruses. These bugs hitch a ride when something, like a file, is shared between computers. This often happens via attachments sent in email or shared USB drives.

我们先从病毒说起。 像文件夹这样的分享文档便是电脑病毒的载体，它们通常隐藏在电子邮件的附件或U盘里。