Matt Tait, a former GCHQ operator who tweets from the handle @pwnallthethings, was particularly prolific. Hours after the first Guccifer 2.0 dump, on the evening of June 15, Tait found something curious. One of the first leaked files had been modified on a computer using Russian-language settings by a user named "Feliks Dzerzhinsky." Dzerzhinsky was the founder of the Cheka, the Soviet secret police—a figure whose mythic renown was signaled by a fifteen-ton bronze statue that once stood in front of KGB headquarters. Tait tweeted an image of the document's metadata settings, which, he suggested, revealed a failure of operational security.
A second mistake had to do with the computer that had been used to control the hacking operation. Researchers found that the malicious software, or malware, used to break into the DNC was controlled by a machine that had been involved in a 2015 hack of the German parliament. German intelligence later traced the Bundestag breach to the Russian GRU, aka Fancy Bear.
There were other errors, too, including a Russian smile emoji—")))"—and emails to journalists that explicitly associated Guccifer 2.0 with DC Leaks, as the cybersecurity firm ThreatConnect pointed out. But the hackers' gravest mistake involved the emails they'd used to initiate their attack. As part of a so-called spear-phishing campaign, Fancy Bear had emailed thousands of targets around the world. The emails were designed to trick their victims into clicking a link that would install malware or send them to a fake but familiar-looking login site to harvest their passwords. The malicious links were hidden behind short URLs of the sort often used on Twitter.
To manage so many short URLs, Fancy Bear had created an automated system that used a popular link-shortening service called Bitly. The spear-phishing emails worked well—one in seven victims revealed their passwords—but the hackers forgot to set two of their Bitly accounts to "private." As a result, a cybersecurity company called SecureWorks was able to glean information about Fancy Bear's targets. Between October 2015 and May 2016, the hacking group used nine thousand links to attack about four thousand Gmail accounts, including targets in Ukraine, the Baltics, the United States, China, and Iran. Fancy Bear tried to gain access to defense ministries, embassies, and military attachés. The largest group of targets, some 40 percent, were current and former military personnel. Among the group's recent breaches were the German parliament, the Italian military, the Saudi foreign ministry, the email accounts of Philip Breedlove, Colin Powell, and John Podesta—Hillary Clinton's campaign chairman—and, of course, the DNC.