News

What’s at stake?

We reported last week that popular Chinese iOS apps were compromised in an unprecedented malware attack. We discovered that the source of the infection was compromised copies of Xcode hosted on Baidu Pan. Apple has published an article urging developers to download Xcode directly from the Mac App Store, or from the Apple Developer website and validate signatures. We’ve now discovered that even if a developer uses a download link seemingly from Apple, he might still be possible to obtain a compromised copy of Xcode.

Please note that we do not have evidence that such attacks has happened. But it is an easy attack that anyone can implement.

How does it work?

This compromise happened because of Xunlei. Xunlei is the most popular download manager in China. Much of its popularity is due to the fact they can accelerate download speeds by pulling resources from other Xunlei users as well as cached copies on the Xunlei server. All of this, however, is invisible to users. Users can simply enter a regular http download address into Xunlei  download manager and the download will start. Chinese developers were using direct download addresses such as http://adcdownload.apple.com/Developer_Tools/Xcode_7/Xcode_7.dmg to download Xcode.

你们的公司有责任尊重人权，防止您的业务被侵犯。我们知道，中国是你们公司的一个重要市场，但恳请您在美国促进和保护人权的同时，也同样在中国致力于此。习主席的访问和美中互联网产业论坛是一个理想的机会，明确表示你的公司将会捍卫隐私权，反对成为监控同谋，将它们的强大在中国和美国一视同仁。

What happened?

According to recent reports, some versions of Xcode used by developers in China have been compromised and are being used to inject tracking codes in iOS apps without developer knowledge. (1,2). Unaware of the injection, those developers then released their compromised iOS apps to the App Store which were then later approved by Apple. At the time of writing this post, the compromised apps are still available in the App store. Any user who has installed and launched these compromised apps will be a victim of these tracking codes.

This is a significant compromise of Apple’s app store. Apple notoriously manually reviews all app submissions and, in comparison to Android stores, has been relatively malware-free. This is the most widespread and significant spread of malware in the history of the Apple app store, anywhere in the world.

The compromised version of Xcode was hosted on Baidu Pan. It is unlikely that Baidu was aware of the compromised version of Xcode. The company removed the files yesterday when news of the compromise surfaced. Because of slow download speeds from foreign websites in China, many Chinese developers prefer to download apps from domestic websites. Many Chinese also use download software like Xunlei, rather than downloading directly from the official Mac App Store.

According to users reports, many prominent Chinese apps are affected. We have included links to the compromised apps in the list below but DO NOT DOWNLOAD these apps. We are simply linking to them so that users can recognize the apps. Affected apps include:  

Wechat The most popolar messaging app in China 

英文原文来自 https://blog.torproject.org/blog/learning-more-about-gfws-active-probing...

Roya, David, Nick, nweaver, Vern, 和我刚刚完成了关于GFW主动探测系统的研究。这个系统在几年前就被用来探测翻墙工具，比如Tor。我们在之前的博文中介绍过GFW主动探测系统是如何工作的。但有几个问题我们没有回答。比如这个系统的物理结构是怎样的。那些用来主动探测的IP是归GFW所有的么？ 有猜测GFW短时间内劫持了部分IP来用来主动探测，但没有证据。这次研究回答了这些问题。

因为这个实验是网络检测，我们从收集数据开始。我们创建了3个数据库，包括了GFW主动探测的小时/月份/年份的数据。这3个不同时段的数据库让我们从不同角度了解GFW主动探测的工作原理。我们公开了其中的两个数据库，你可以重复我们的实验，或者自己分析。

• 通常来说，如果Tor的某个网桥代理被GFW检测并封锁，它会一直被封锁。但是这意味着网桥代理完全无法访问吗？ 我们让中国的VPS一直连接我们控制的网桥代理。我们发现，每25小时，中国的VPS可以短暂的连接到我们的代理网桥。下图显示了这个现象。每个数据点表示中国的VPS试图与网桥代理建立连接。中国联通和中国教育网都有这个周期性现象。有时候，网络安全设备在更新规则时会默认允许所有流量，但我们不知道GFW周期性现象是不是因为这个原因导致的。

• 我们找到了规律，GFW主动探测的TCP头暗示那几千个IP都来自与同一个地方。下图显示了数据包的初始序号和时间。每个数据点都是一个主动探测连接。如果每个主动探测都是从不同地方发出的，我们应该看到随机的数据点，因为数据包的初始序号是随机选择的。但是下图显示主动探测连接虽然来自不同IP，但是非常有规律。我们认为主动探测的初始序号是按照时间产生的。

 

• 我们发现GFW主动探测不仅仅针对了Tor。GFW还对 SoftEther 和GoAgent进行了主动探测。这说明主动探测系统是模块化的。GFW工程师能比较简单的对新翻墙软件改进主动探测功能。

We have been critical of Wikipedia’s approach to censorship in the Middle Kingdom. In a recent piece for the Huffington Post, I lamented the loss of Wikipedia in China. The encyclopedia’s founder, Jimmy Wales, who is also a staunch and public anti-censorship champion, reached out to us on Twitter. Jimmy agreed to publish our unedited exchange on the difficult nature of dealing with censorship in China.

What happened?

ShawdowSocks

On August 22, an open source project called ShadowSocks was removed from GitHub.

According to the project’s author, the police contacted him and asked him to stop working on the tool and to remove all of the code from GitHub.

He later removed the reference of the police, presumably under the pressure of the police.

After the news, many Chinese and foreign developers, as well as ShadowSocks users, paid tribute to the author. As a result of this attention, ShadowSocks became the top trending project on GitHub.

 

When LinkedIn decided to create a China-hosted version of its website in February, 2014, it made a decision to compromise the company's values in the pursuit of the dollar.

It's important to note that before LinkedIn launched LingYing (the local version of the site), LinkedIn was already active in China. By their own account, they had four million registered users (with little marketing effort), a Chinese-language interface and China-based clients who were buying recruitment ads on the platform (the major source of their revenue). The site had been blocked by the authorities for one 24-hour period but otherwise was always accessible.

So why was it necessary for LinkedIn to create a local entity in China? With a local entity the company would be able to issue official receipts in RMB, making it more convenient for local companies to buy advertising on the site. A local entity also makes it easier to secure marketing deals to promote LingYing in China.

But perhaps the biggest appeal in creating a local entity for LinkedIn is that it would be among the few foreign internet companies who could cosy up with Lu Wei and the Cyberspace Administration of China (CAC). Having that kind of a relationship with CAC surely helps the business and those who are associated with the company.