Discord Admins Hacked by Malicious Bookmarks

A number of Discord communities focused on cryptocurrency have been hacked this past month after their administrators were tricked into running malicious Javascript code disguised as a Web browser bookmark.

According to interviews with victims, several of the attacks began with an interview request from someone posing as a reporter for a crypto-focused news outlet online. Those who take the bait are sent a link to a Discord server that appears to be the official Discord of the crypto news site, where they are asked to complete a verification step to validate their identity.

As shown in this Youtube video, the verification process involves dragging a button from the phony crypto news Discord server to the bookmarks bar in one’s Web browser. From there, the visitor is instructed to go back to discord.com and then click the new bookmark to complete the verification process.

However, the bookmark is actually a clever snippet of Javascript that quietly grabs the user’s Discord token and sends it to the scammer’s website. The attacker then loads the stolen token into their own browser session and (usually late at night after the admins are asleep) posts an announcement in the targeted Discord about an exclusive “airdrop,” “NFT mint event” or some other potential money making opportunity for the Discord members.

The unsuspecting Discord members click the link provided by the compromised administrator account, and are asked to connect their crypto wallet to the scammer’s site, where it asks for unlimited spend approvals on their tokens, and subsequently drains the balance of any valuable accounts.

Meanwhile, anyone in the compromised Discord channel who notices the scam and replies is banned, and their messages are deleted by the compromised admin account.

Nicholas Scavuzzo is an associate at Ocean Protocol, which describes itself as an “open-source protocol that aims to allow businesses and individuals to exchange and monetize data and data-based services.” On May 22, an administrator for Ocean Protocol’s Discord server clicked a link in a direct message from a community member that prompted them to prove their identity by dragging a link to their bookmarks.

Scavuzzo, who is based in Maine, said the attackers waited until around midnight in his timezone time before using the administrator’s account to send out an unauthorized message about a new Ocean airdrop.

Scavuzzo said the administrator’s account was hijacked even though she had multi-factor authentication turned on.

“A CAPTCHA bot that allows Discord cookies to be accessed by the person hosting the CAPTCHA,” was how Scavuzzo described the attack. “I’ve seen all kinds of crypto scams, but I’ve never seen one like this.”

Importantly, the stolen token only works for the attackers as long as its rightful owner doesn’t log out and back in, or else change their credentials.

Assuming the administrator can log in, that is. In Ocean’s case, one of the first things the intruders did once they swiped the administrator’s token was change the server’s access controls and remove all core Ocean team members from the server.

Fortunately for Ocean, Scavuzzo was able to reach the operator of the server that hosts the Discord channel, and have the channel’s settings reverted back to normal.

“Thankfully, we are a globally distributed team, so we have people awake at all hours,” Scavuzzo said, noting that Ocean is not aware of any Discord community members who fell for the phony airdrop offer, which was live for about 30 minutes. “This could have been a lot worse.”

On May 26, Aura Network reported on Twitter that its Discord server was compromised in a phishing attack that resulted in the deletion of Discord channels and the dissemination of fake Aura Network Airdrop Campaign links.

On May 27, Nahmii — a cryptocurrency technology based on the Ethereum blockchain — warned on Twitter that one of its community moderators on Discord was compromised and posting fake airdrop details.

On May 9, MetrixCoin reported that its Discord server was hacked, with fake airdrop details pushed to all users.

KrebsOnSecurity recently heard from a trusted source in the cybersecurity industry who dealt firsthand with one of these attacks and asked to remain anonymous.

“I do pro bono Discord security work for a few Discords, and I was approached by one of these fake journalists,” the source said. “I played along and got the link to their Discord, where they were pretending to be journalists from the Cryptonews website using several accounts.”

The source took note of all the Discord IDs of the admins of the fake Cryptonews Discord, so that he could ensure they were blocked from the Discords he helps to secure.

“Since I’ve been doing this for a while now, I’ve built up a substantial database of Discord users and messages, so often I can see these scammers’ history on Discord,” the source said.

In this case, he noticed a user with the “CEO” role in the fake Cryptonews Discord had been seen previously under another username — “Levatax.” Searching on that Discord ID and username revealed a young Turkish coder named Berk Yilmaz whose Github page linked to the very same Discord ID as the scammer CEO.

Reached via instant message on Telegram, Levatax said he’s had no involvement in such schemes, and that he hasn’t been on Discord since his Microsoft Outlook account was hacked months ago.

“The interesting thing [is] that I didn’t use Discord since few months or even social media because of the political status of Turkey,” Levatax explained, referring to the recent election in his country. “The only thing I confirm is losing my Outlook account which connected to my Discord, and I’m already in touch with Microsoft to recover it.”

The verification method used in the above scam involves a type of bookmark called a “bookmarklet” that stores Javascript code as a clickable link in the bookmarks bar at the top of one’s browser.

While bookmarklets can be useful and harmless, malicious Javascript that is executed in the browser by the user is especially dangerous. So please avoid adding (or dragging) any bookmarks or bookmarklets to your browser unless it was your idea in the first place.

What Counts as “Good Faith Security Research?”

The U.S. Department of Justice (DOJ) recently revised its policy on charging violations of the Computer Fraud and Abuse Act (CFAA), a 1986 law that remains the primary statute by which federal prosecutors pursue cybercrime cases. The new guidelines state that prosecutors should avoid charging security researchers who operate in “good faith” when finding and reporting vulnerabilities. But legal experts continue to advise researchers to proceed with caution, noting the new guidelines can’t be used as a defense in court, nor are they any kind of shield against civil prosecution.

In a statement about the changes, Deputy Attorney General Lisa O. Monaco said the DOJ “has never been interested in prosecuting good-faith computer security research as a crime,” and that the new guidelines “promote cybersecurity by providing clarity for good-faith security researchers who root out vulnerabilities for the common good.”

What constitutes “good faith security research?” The DOJ’s new policy (PDF) borrows language from a Library of Congress rulemaking (PDF) on the Digital Millennium Copyright Act (DMCA), a similarly controversial law that criminalizes production and dissemination of technologies or services designed to circumvent measures that control access to copyrighted works. According to the government, good faith security research means:

“…accessing a computer solely for purposes of good-faith testing, investigation, and/or correction of a security flaw or vulnerability, where such activity is carried out in a manner designed to avoid any harm to individuals or the public, and where the information derived from the activity is used primarily to promote the security or safety of the class of devices, machines, or online services to which the accessed computer belongs, or those who use such devices, machines, or online services.”

“Security research not conducted in good faith — for example, for the purpose of discovering security holes in devices, machines, or services in order to extort the owners of such devices, machines, or services — might be called ‘research,’ but is not in good faith.”

The new DOJ policy comes in response to a Supreme Court ruling last year in Van Buren v. United States (PDF), a case involving a former police sergeant in Florida who was convicted of CFAA violations after a friend paid him to use police resources to look up information on a private citizen.

But in an opinion authored by Justice Amy Coney Barrett, the Supreme Court held that the CFAA does not apply to a person who obtains electronic information that they are otherwise authorized to access and then misuses that information.

Orin Kerr, a law professor at University of California, Berkeley, said the DOJ’s updated policy was expected given the Supreme Court ruling in the Van Buren case. Kerr noted that while the new policy says one measure of “good faith” involves researchers taking steps to prevent harm to third parties, what exactly those steps might constitute is another matter.

“The DOJ is making clear they’re not going to prosecute good faith security researchers, but be really careful before you rely on that,” Kerr said. “First, because you could still get sued [civilly, by the party to whom the vulnerability is being reported], but also the line as to what is legitimate security research and what isn’t is still murky.”

Kerr said the new policy also gives CFAA defendants no additional cause for action.

“A lawyer for the defendant can make the pitch that something is good faith security research, but it’s not enforceable,” Kerr said. “Meaning, if the DOJ does bring a CFAA charge, the defendant can’t move to dismiss it on the grounds that it’s good faith security research.”

Kerr added that he can’t think of a CFAA case where this policy would have made a substantive difference.

“I don’t think the DOJ is giving up much, but there’s a lot of hacking that could be covered under good faith security research that they’re saying they won’t prosecute, and it will be interesting to see what happens there,” he said.

The new policy also clarifies other types of potential CFAA violations that are not to be charged. Most of these include violations of a technology provider’s terms of service, and here the DOJ says “violating an access restriction contained in a term of service are not themselves sufficient to warrant federal criminal charges.” Some examples include:

-Embellishing an online dating profile contrary to the terms of service of the dating website;
-Creating fictional accounts on hiring, housing, or rental websites;
-Using a pseudonym on a social networking site that prohibits them;
-Checking sports scores or paying bills at work.

ANALYSIS

Kerr’s warning about the dangers that security researchers face from civil prosecution is well-founded. KrebsOnSecurity regularly hears from security researchers seeking advice on how to handle reporting a security vulnerability or data exposure. In most of these cases, the researcher isn’t worried that the government is going to come after them: It’s that they’re going to get sued by the company responsible for the security vulnerability or data leak.

Often these conversations center around the researcher’s desire to weigh the rewards of gaining recognition for their discoveries with the risk of being targeted with costly civil lawsuits. And almost just as often, the source of the researcher’s unease is that they recognize they might have taken their discovery just a tad too far.

Here’s a common example: A researcher finds a vulnerability in a website that allows them to individually retrieve every customer record in a database. But instead of simply polling a few records that could be used as a proof-of-concept and shared with the vulnerable website, the researcher decides to download every single file on the server.

Not infrequently, there is also concern because at some point the researcher suspected that their automated activities might have actually caused stability or uptime issues with certain services they were testing. Here, the researcher is usually concerned about approaching the vulnerable website or vendor because they worry their activities may already have been identified internally as some sort of external cyberattack.

What do I take away from these conversations? Some of the most trusted and feared security researchers in the industry today gained that esteem not by constantly taking things to extremes and skirting the law, but rather by publicly exercising restraint in the use of their powers and knowledge — and by being effective at communicating their findings in a way that maximizes the help and minimizes the potential harm.

If you believe you’ve discovered a security vulnerability or data exposure, try to consider first how you might defend your actions to the vulnerable website or vendor before embarking on any automated or semi-automated activity that the organization might reasonably misconstrue as a cyberattack. In other words, try as best you can to minimize the potential harm to the vulnerable site or vendor in question, and don’t go further than you need to prove your point.