苹果操作系统安全性相对较高，我已经就该主题发表过几篇文章，也从PC用户那里获得了很多这样的反馈【参见《为什么苹果电脑不会中病毒》（Why are there no Mac viruses）】。因此，我觉得有必要告诉大家，苹果操作系统目前似乎正在经历迄今为止最为严重的恶意软件攻击。

    根据俄罗斯大蜘蛛防病毒软件公司（Dr.Web）上周三发布的一份报告，称Flashback木马已经对全球范围内超过55万台Mac电脑的安全造成了威胁。

    Dr. Web已经针对微软Windows系统若干种版本的Flashback木马提供了杀毒程序。它对苹果电脑遭遇的木马病毒变种描述如下：

    这种病毒变种会用Java语言代码来装载包含漏洞利用（exploit）的Java小应用程序，然后把可执行文件保存至中毒的Mac电脑硬盘。病毒利用该文件从远程服务器下载恶意负载并启动。依照从服务器获取的指令，它能获取并运行任何可执行文件。

    甲骨文公司（Oracle）在2010年收购太阳微系统公司（Sun Microsystems）后承担了Java程序语言的责任，并于今年2月份发布了漏洞更新。科技博客Ars Technica的程雅基称：“Flashback最新变种的消息流传开之后，苹果公司直到上周初才发布了补救措施。”

    i该补救措施是苹果操作系统软件更新Java for OS X 2012-001的一部分。用户可以在“系统设置”下的“软件更新”中找到。如果要检查自己的Mac是否中毒，可以根据 F-Secure杀毒软件的查毒指南，使用“实用程序文件夹”的“终端应用软件”来排查木马：

    Having written several times -- and taken a lot of heat from PC users -- about the relative security of Apple's (AAPL) operating systems (See Why are there no Mac viruses), I feel obliged to report that Mac OS X is under what appears to be the most serious malware attack to date.

    According to a report posted Wednesday by Dr. Web, a Russian anti-virus vendor that may have a stick in this fire, the security of more than 550,000 Macs around the world have been compromised by the Flashback trojan.

    Dr. Web, which sells an antidote for the versions of Flashback that run on Microsoft (MSFT) Windows machines, describes the Mac variant like this:

    JavaScript code is used to load a Java-applet containing an exploit... The exploit saves an executable file onto the hard drive of the infected Mac machine. The file is used to download malicious payload from a remote server and to launch it...It may get and run any executable specified in a directive received from a server.

    Oracle (ORCL), which assumed responsibility for the Java programming language when it acquired Sun Microsystems in 2010, released a fix for the vulnerability in February. According to Ars Technica's Jacqui Cheng, "Apple didn't send out a fix until earlier this week, after news began to spread about the latest Flashback variant."

    The fix is part of the OS X software update called Java for OS X 2012-001. You'll find it in Software Update in System Preferences. If you think one of your Macs is infected, F-Secure has instructions on how to use the Terminal application in your Utilities folder to find out: