On March 19 of this year, Hillary Clinton's campaign chairman John Podesta received an alarming email that appeared to come from Google.
The email, however, didn't come from the internet giant. It was actually an attempt to hack into his personal account. In fact, the message came from a group of hackers that security researchers, as well as the US government, believe are spies working for the Russian government. At the time, however, Podesta didn't know any of this, and he clicked on the malicious link contained in the email, giving hackers access to his account.
Read more: We Spoke to DNC Hacker 'Guccifer 2.0'
Months later, on October 9, WikiLeaks began publishing thousands of Podesta's hacked emails. Almost everyone immediately pointed the finger at Russia, who is suspected of being behind a long and sophisticated hacking campaign that has the apparent goal of influencing the upcoming US elections. But there was no public evidence proving the same group that targeted the Democratic National Committee was behind the hack on Podesta—until now.
The data linking a group of Russian hackers—known as Fancy Bear, APT28, or Sofacy—to the hack on Podesta is also yet another piece in a growing heap of evidence pointing toward the Kremlin. And it also shows a clear thread between apparently separate and independent leaks that have appeared on a website called DC Leaks, such as that of Colin Powell's emails; and the Podesta leak, which was publicized on WikiLeaks.
All these hacks were done using the same tool: malicious short URLs hidden in fake Gmail messages. And those URLs, according to a security firm that's tracked them for a year, were created with Bitly account linked to a domain under the control of Fancy Bear.
THE TRAIL THAT LEADS TO FANCY BEAR
The phishing email that Podesta received on March 19 contained a URL, created with the popular Bitly shortening service, pointing to a longer URL that, to an untrained eye, looked like a Google link.
Inside that long URL, there's a 30-character string that looks like gibberish but is actually the encoded Gmail address of John Podesta. According to Bitly's own statistics, that link, which has never been published, was clicked two times in March.
That's the link that opened Podesta's account to the hackers, a source close to the investigation into the hack confirmed to Motherboard.
That link is only one of almost 9,000 links Fancy Bear used to target almost 4,000 individuals from October 2015 to May 2016. Each one of these URLs contained the email and name of the actual target. The hackers created them with with two Bitly accounts in their control, but forgot to set those accounts to private, according to SecureWorks, a security firm that's been tracking Fancy Bear for the last year.
SecureWorks was tracking known Fancy Bear command and control domains. One of these lead to a Bitly shortlink, which led to the Bitly account, which led to the thousands of Bitly URLs that were later connected to a variety of attacks, including on the Clinton campaign. With this privileged point of view, for example, the researchers saw Fancy Bear using 213 short links targeting 108 email addresses on the hillaryclinton.com domain, as the company explained in a somewhat overlooked report earlier this summer, and as BuzzFeed reported last week.
Using Bitly allowed "third parties to see their entire campaign including all their targets— something you'd want to keep secret," Tom Finney, a researcher at SecureWorks, told Motherboard.
It was one of Fancy Bear's "gravest mistakes," as Thomas Rid, a professor at King's College who has closely studied the case, put it in a new piece published on Thursday in Esquire, as it gave researchers unprecedented visibility into the activities of Fancy Bear, linking different parts of its larger campaign together.
This is how researchers have been able to find the phishing link that tricked Colin Powell and got him hacked. This also allowed them to confirm other public reports of compromises, such as that of William Rinehart, a staffer with Clinton's presidential campaign. As The Smoking Gun reported in August, Rinehart received a malicious Google security alert on March 22, according to a screenshot Rinehart shared with the site. SecureWorks found a URL that had Rinehart's Gmail address encoded, which had the same date.
Similar malicious emails and short URLs have also been used recently against independent journalists from Bellingcat, a website that has investigated the incident of the shootdown of Malaysian Airlines Flight 17 (MH17) over Ukraine in 2014, finding evidence that Russian-backed rebels were behind it.
Other journalists in eastern Europe have also recently been targeted with phishing emails trying to break into their Gmail accounts.
These malicious emails, just like the ones used against Podesta, Powell, Rinehart and many others, looked like Google alerts, and contained the same type of encoded strings hiding the victims' names.
It's unclear why the hackers used the encoded strings, which effectively reveal their targets to anyone. Kyle Ehmke, a threat intelligence researcher at security firm ThreatConnect, argued that "the strings might help them keep track of or better organize their operations, tailor credential harvesting pages to specific victims, monitor the effectiveness of their operations, or diffuse their operations against various targets across several URLs to facilitate continuity should one of the URLs be discovered."
The use of popular link shortening services such as Bitly or Tinyurl might have a simpler explanation. According to Rid, the hackers probably wanted to make sure their phishing attempts went past their targets' spam filters.
THE SMOKING GUN?
None of this new data constitutes a smoking gun that can clearly frame Russia as the culprit behind the almost unprecedented hacking campaign that has hit the DNC and several other targets somewhat connected to the US presidential election.
Almost two weeks ago, the US government took the rare step of publicly pointing the finger at the Russian government, accusing it of directing the recent string of hacks and data breaches. The intelligence community declined to explain how they reached their conclusion, and it's fair to assume they have data no one else can see.
"They don't want to understand the evidence."
This newly uncovered data paints an even clearer picture for the public, showing a credible link between the several leaking outlets chosen by the hackers, and, once again, pointing toward Fancy Bear, a notorious hacking group that's widely believed to be connected with the Russian government. While there are still naysayers, including presidential candidate and former reality TV star Donald Trump, for many, the debate over who hacked the DNC, and who's behind all this hacking, is pretty much closed.
"We are approaching the point in this case where there are only two reasons for why people say there's no good evidence," Rid told me. "The first reason is because they don't understand the evidence—because the don't have the necessary technical knowledge. The second reason is they don't want to understand the evidence."
UPDATE, 10/20/2016, 4:31 p.m.: After publication of this story, Bitly sent Motherboard a statement to say the company can only do so much to prevent malicious actors from using its service, as it "cannot proactively police our customers' private data without compromising our commitment to their privacy."
"The links and accounts related to this situation were blocked as soon as we were informed. This is not an exploit of Bitly, but an unfortunate exploit of Internet users through social engineering. It serves as a reminder that even the savviest, most skeptical users can be vulnerable to opening unsolicited emails," the statement read.
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