Security Engineering. Ross Anderson. Читать онлайн. Newlib. NEWLIB.NET

Автор: Ross Anderson
Издательство: John Wiley & Sons Limited
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Жанр произведения: Зарубежная компьютерная литература
Год издания: 0
isbn: 9781119642817
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href="#u16231f12-08ee-5d10-94e9-ca7e981347c8">Chapter 26).

      Given a high-value target, there's a big bag of tools the analyst can install on their laptop or cellphone directly. They can locate it physically, turn it into a room bug and even use it as a remote camera. They can download the target's address book and contact history and feed that into Xkeyscore to search recursively for their direct and indirect contacts. Meanwhile the analyst can bug messaging apps, beating the end-to-end encryption by collecting the call contents once they've been decrypted. They can set up an alarm to notify them whenever the target sends or receives messages of interest, or changes location. The coverage is pretty complete. And when it's time for the kill, the target's phone can be used to guide a bomb or a missile. Little wonder Ed Snowden insisted that journalists interviewing him put their phones in the fridge!

      Finally, the analyst has also a proxy through which they can access the Internet surreptitiously – typically a machine on a botnet. It might even be the PC in your home office.

       2.2.1.11 Offensive operations

      The Director NSA also heads the US Cyber Command, which since 2009 has been one of ten unified commands of the United States Department of Defense. It is responsible for offensive cyber operations, of which the one that made a real difference was Stuxnet. This was a worm designed to damage Iran's uranium enrichment centrifuges by speeding them up and slowing them down in patterns designed to cause mechanical damage, and was developed jointly by the USA and Israel [326, 827]. It was technically sophisticated, using four zero-day exploits and two stolen code-signing certificates to spread promiscuously through Windows PCs, until it found Siemens programmable logic controllers of the type used at Iran's Natanz enrichment plant – where it would then install a rootkit that would issue the destructive commands, while the PC assured the operators that everything was fine. It was apparently introduced using USB drives to bridge the air gap to the Iranian systems, and came to light in 2010 after copies had somehow spread to central Asia and Indonesia. Two other varieties of malware (Flame and Duqu) were then discovered using similar tricks and common code, performing surveillance at a number of companies in the Middle East and South Asia; more recent code-analysis tools have traced a lineage of malware that goes back to 2002 (Flowershop) and continued to operate until 2016 (with the Equation Group tools) [2071].

      Stuxnet acted as a wake-up call for other governments, which rushed to acquire ‘cyber-weapons’ and develop offensive cyber doctrine – a set of principles for what cyber warriors might do, developed with some thought given to rationale, strategy, tactics and legality. Oh, and the price of zero-day vulnerabilities rose sharply.

       2.2.1.12 Attack scaling

      Computer scientists know the importance of how algorithms scale, and exactly the same holds for attacks. Tapping a single mobile phone is hard. You have to drive around behind the suspect with radio and cryptanalysis gear in your car, risk being spotted, and hope that you manage to catch the suspect's signal as they roam from one cell to another. Or you can drive behind them with a false base station7 and hope their phone will roam to it as the signal is louder than the genuine one; but then you risk electronic detection too. Both are highly skilled work and low-yield: you lose the signal maybe a quarter of the time. So if you want to wiretap someone in central Paris often enough, why not just wiretap everyone? Put antennas on your embassy roof, collect it all, write the decrypted calls and text messages into a database, and reconstruct the sessions electronically. If you want to hack everyone in France, hack the telco, perhaps by subverting the equipment it uses. At each stage the capital cost goes up but the marginal cost of each tap goes down. The Five Eyes strategy is essentially to collect everything in the world; it might cost billions to establish and maintain the infrastructure, but once it's there you have everything.

      China is now the leading competitor to the USA, being second not just in terms of GDP but as a technology powerhouse. The Chinese lack the NSA's network of alliances and access to global infrastructure (although they're working hard at that). Within China itself, however, they demand unrestricted access to local data. Some US service firms used to operate there, but trouble followed. After Yahoo's systems were used to trap the dissident Wang Xiaoning in 2002, Alibaba took over Yahoo's China operation in 2005; but there was still a row when Wang's wife sued Yahoo in US courts in 2007, and showed that Yahoo had misled Congress over the matter [1764]. In 2008, it emerged that the version of Skype available in China had been modified so that messages were scanned for sensitive keywords and, if they were found, the user's texts were uploaded to a server in China [1963]. In December 2009, Google discovered a Chinese attack on its corporate infrastructure, which became known as Operation Aurora; Chinese agents had hacked into the Google systems used to do wiretaps for the FBI (see Prism above) in order to discover which of their own agents in the USA were under surveillance. Google had already suffered criticism for operating a censored version of their search engine for Chinese users, and a few months later, they pulled out of China. By this time, Facebook, Twitter and YouTube had already been blocked. A Chinese strategy was emerging of total domestic control, augmented by ever-more aggressive collection overseas.

      From about 2002, there had been a series of hacking attacks on US and UK defence agencies and contractors, codenamed ‘Titan Rain’ and ascribed to the Chinese armed forces. According to a 2004 study by the US Foreign Military Studies Office (FMSO), Chinese military doctrine sees the country in a state of war with the West; we are continuing the Cold War by attacking China, trying to overthrow its communist regime by exporting subversive ideas to it over the Internet [1884]. Chinese leaders see US service firms, news websites and anonymity tools such as Tor (which the State Department funds so that Chinese and other people can defeat censorship) as being of one fabric with the US surveillance satellites and aircraft that observe their military defences. Yahoo and Google were thus seen as fair game, just like Lockheed Martin and BAe.

      Our own group's first contact with the Chinese came in 2008. We were asked for help by the Dalai Lama, who had realised that the Chinese had hacked his office systems in the run-up to the Beijing Olympics that year. One of my research students, Shishir Nagaraja, happened to be in Delhi waiting for his UK visa to be renewed, so he volunteered to go up to the Tibetan HQ in Dharamsala and run some forensics. He found that about 35 of the 50 PCs in the office of the Tibetan government in exile had been hacked; information was being siphoned off to China, to IP addresses located near the three organs of Chinese state security charged with different aspects of Tibetan affairs. The attackers appear to have got in by sending one of the monks an email that seemed to come from a colleague; when he clicked on the attached PDF, it had a JavaScript buffer overflow that used a vulnerability in Adobe Reader