Image: Shutterstock, iHaMoo.

Adam Griffin is still in disbelief over how quickly he was robbed of nearly $500,000 in cryptocurrencies. A scammer called using a real Google phone number to warn his Gmail account was being hacked, sent email security alerts directly from google.com, and ultimately seized control over the account by convincing him to click “yes” to a Google prompt on his mobile device.

Griffin is a battalion chief firefighter in the Seattle area, and on May 6 he received a call from someone claiming they were from Google support saying his account was being accessed from Germany. A Google search on the phone number calling him — (650) 203-0000 — revealed it was an official number for Google Assistant, an AI-based service that can engage in two-way conversations.

At the same time, he received an email that came from a google.com email address, warning his Google account was compromised. The message included a “Google Support Case ID number” and information about the Google representative supposedly talking to him on the phone, stating the rep’s name as “Ashton” — the same name given by the caller.

Griffin didn’t learn this until much later, but the email he received had a real google.com address because it was sent via Google Forms, a service available to all Google Docs users that makes it easy to send surveys, quizzes and other communications.

A phony security alert Griffin received prior to his bitcoin heist, via Google Forms.

According to tripwire.com’s Graham Cluely, phishers will use Google Forms to create a security alert message, and then change the form’s settings to automatically send a copy of the completed form to any email address entered into the form. The attacker then sends an invitation to complete the form to themselves, not to their intended victim.

“So, the attacker receives the invitation to fill out the form – and when they complete it, they enter their intended victim’s email address into the form, not their own,” Cluely wrote in a December 2023 post. “The attackers are taking advantage of the fact that the emails are being sent out directly by Google Forms (from the google.com domain). It’s an established legitimate domain that helps to make the email look more legitimate and is less likely to be intercepted en route by email-filtering solutions.”

The fake Google representative was polite, patient, professional and reassuring. Ashton told Griffin he was going to receive a notification that would allow him to regain control of the account from the hackers. Sure enough, a Google prompt instantly appeared on his phone asking, “Is it you trying to recover your account?”

Adam Griffin clicked “yes,” to an account recovery notification similar to this one on May 6.

Griffin said that after receiving the pop-up prompt from Google on his phone, he felt more at ease that he really was talking to someone at Google. In reality, the thieves caused the alert to appear on his phone merely by stepping through Google’s account recovery process for Griffin’s Gmail address.

“As soon as I clicked yes, I gave them access to my Gmail, which was synched to Google Photos,” Griffin said.

Unfortunately for Griffin, years ago he used Google Photos to store an image of the secret seed phrase that was protecting his cryptocurrency wallet. Armed with that phrase, the phishers could drain all of his funds.

“From there they were able to transfer approximately $450,000 out of my Exodus wallet,” Griffin recalled.

Griffin said just minutes after giving away access to his Gmail account he received a call from someone claiming to be with Coinbase, who likewise told him someone in Germany was trying to take over his account.

Griffin said a follow-up investigation revealed the attackers had used his Gmail account to gain access to his Coinbase account from a VPN connection in California, providing the multi-factor code from his Google Authenticator app. Unbeknownst to him at the time, Google Authenticator by default also makes the same codes available in one’s Google account online.

But when the thieves tried to move $100,000 worth of cryptocurrency out of his account, Coinbase sent an email stating that the account had been locked, and that he would have to submit additional verification documents before he could do anything with it.

GRAND THEFT AUTOMATED

Just days after Griffin was robbed, a scammer impersonating Google managed to phish 45 bitcoins — approximately $4,725,000 at today’s value — from Tony, a 42-year-old professional from northern California. Tony agreed to speak about his harrowing experience on condition that his last name not be used.

Tony got into bitcoin back in 2013 and has been investing in it ever since. On the evening of May 15, 2024, Tony was putting his three- and one-year-old boys to bed when he received a message from Google about an account security issue, followed by a phone call from a “Daniel Alexander” at Google who said his account was compromised by hackers.

Tony said he had just signed up for Google’s Gemini AI (an artificial intelligence platform formerly known as “Bard”), and mistakenly believed the call was part of that service. Daniel told Tony his account was being accessed by someone in Frankfurt, Germany, and that he could evict the hacker and recover access to the account by clicking “yes” to the prompt that Google was going to send to his phone.

The Google prompt arrived seconds later. And to his everlasting regret, Tony clicked the “Yes, it’s me” button.

Then came another call, this one allegedly from security personnel at Trezor, a company that makes encrypted hardware devices made to store cryptocurrency seed phrases securely offline. The caller said someone had submitted a request to Trezor to close his account, and they forwarded Tony a message sent from his Gmail account that included his name, Social Security number, date of birth, address, phone number and email address.

Tony said he began to believe then that his Trezor account truly was compromised. The caller convinced him to “recover” his account by entering his cryptocurrency seed phrase at a phishing website (verify-trezor[.]io) that mimicked the official Trezor website.

“At this point I go into fight or flight mode,” Tony recalled. “I’ve got my kids crying, my wife is like what the heck is going on? My brain went haywire. I put my seed phrase into a phishing site, and that was it.”

Almost immediately, all of the funds he was planning to save for retirement and for his children’s college fund were drained from his account.

“I made mistakes due to being so busy and not thinking correctly,” Tony told KrebsOnSecurity. “I had gotten so far away from the security protocols in bitcoin as life had changed so much since having kids.”

Tony shared this text message exchange of him pleading with his tormentors after being robbed of 45 bitcoins.

Tony said the theft left him traumatized and angry for months.

“All I was thinking about was protecting my boys and it ended up costing me everything,” he said. “Needless to say I’m devastated and have had to do serious therapy to get through it.”

MISERY LOVES COMPANY

Tony told KrebsOnSecurity that in the weeks following the theft of his 45 bitcoins, he became so consumed with rage and shame that he was seriously contemplating suicide. Then one day, while scouring the Internet for signs that others may have been phished by Daniel, he encountered Griffin posting on Reddit about the phone number involved in his recent bitcoin theft.

Griffin said the two of them were initially suspicious of each other — exchanging cautious messages for about a week — but he decided Tony was telling the truth after contacting the FBI agent that Tony said was working his case. Comparing notes, they discovered the fake Google security alerts they received just prior to their individual bitcoin thefts referenced the same phony “Google Support Case ID” number.

Adam Griffin and Tony said they received the same Google Support Case ID number in advance of their thefts. Both were sent via Google Forms, which sends directly from the google.com domain name.

More importantly, Tony recognized the voice of “Daniel from Google” when it was featured in an interview by Junseth, a podcaster who covers cryptocurrency scams. The same voice that had coaxed Tony out of his considerable cryptocurrency holdings just days earlier also had tried to phish Junseth, who played along for several minutes before revealing he knew it was a scam.

Daniel told Junseth he was a teenager and worked with other scam callers who had all met years ago on the game Minecraft, and that he recently enjoyed a run of back-to-back Gmail account compromises that led to crypto theft paydays.

“No one gets arrested,” Daniel enthused to Junseth in the May 7 podcast, which quickly went viral on social media. “It’s almost like there’s no consequences. I have small legal side hustles, like businesses and shit that I can funnel everything through. If you were to see me in real life, I look like a regular child going to school with my backpack and shit, you’d never expect this kid is stealing all this shit.”

Daniel explained that they often use an automated bot that initiates calls to targets warning that their account is experiencing suspicious activity, and that they should press “1” to speak with a representative. This process, he explained, essentially self-selects people who are more likely to be susceptible to their social engineering schemes. [It is possible — but not certain — that this bot Daniel referenced explains the incoming call to Griffin from Google Assistant that precipitated his bitcoin heist].

Daniel told Junseth he and his co-conspirators had just scored a $1.2 million theft that was still pending on the bitcoin investment platform SwanBitcoin. In response, Junseth tagged SwanBitcoin in a post about his podcast on Twitter/X, and the CEO of Swan quickly replied that they caught the $1.2 million transaction that morning.

Apparently, Daniel didn’t appreciate having his voice broadcast to the world (or his $1.2 million bitcoin heist disrupted) because according to Junseth someone submitted a baseless copyright infringement claim about it to Soundcloud, which was hosting the recording.

The complaint alleged the recording included a copyrighted song, but that wasn’t true: Junseth later posted a raw version of the recording to Telegram, and it clearly had no music in the background. Nevertheless, Soundcloud removed the audio file.

“All these companies are very afraid of copyright,” Junseth explained in a May 2024 interview with the podcast whatbitcoindid.com, which features some of the highlights from his recorded call with Daniel.

“It’s interesting because copyright infringement really is an act that you’re claiming against the publisher, but for some reason these companies have taken a very hard line against it, so if you even claim there’s copyrighted material in it they just take it down and then they leave it to you to prove that you’re innocent,” Junseth said. “In Soundcloud’s instance, part of declaring your innocence is you have to give them your home address and everything else, and it says right on there, ‘this will be provided to the person making the copyright claim.’”

AFTERMATH

When Junseth asked how potential victims could protect themselves, Daniel explained that if the target doesn’t have their Google Authenticator synced to their Google cloud account, the scammers can’t easily pivot into the victim’s accounts at cryptocurrency exchanges, as they did with Griffin.

By default, Google Authenticator syncs all one-time codes with a Gmail user’s account, meaning if someone gains access to your Google account, they can then access all of the one-time codes handed out by your Google Authenticator app.

To change this setting, open Authenticator on your mobile device, select your profile picture, and then choose “Use without an Account” from the menu. If you disable this, it’s a good idea to keep a printed copy of one-time backup codes, and to store those in a secure place.

You may also wish to download Google Authenticator to another mobile device that you control. Otherwise, if you turn off cloud synching and lose that sole mobile device with your Google Authenticator app, it could be difficult or impossible to recover access to your account if you somehow get locked out.

Griffin told KrebsOnSecurity he had no idea it was so easy for thieves to take over his account, and to abuse so many different Google services in the process.

“I know I definitely made mistakes, but I also know Google could do a lot better job protecting people,” he said.

In response to questions from KrebsOnSecurity, Google said it can confirm that this was a narrow phishing campaign, reaching a “very small group of people.”

“We’re aware of this narrow and targeted attack, and have hardened our defenses to block recovery attempts from this actor,” the company said in a written statement, which emphasized that the real Google will never call you.

“While these types of social engineering campaigns are constantly evolving, we are continuously working to harden our systems with new tools and technical innovations, as well as sharing updated guidance with our users to stay ahead of attackers,” the statement reads.

Both Griffin and Tony say they continue to receive “account security” calls from people pretending to work for Google or one of the cryptocurrency platforms.

“It’s like you get put on some kind of list, and then those lists get recycled over and over,” Tony said.

Griffin said that for several months after his ordeal, he accepted almost every cryptocurrency scam call that came his way, playing along in the vain hope of somehow tricking the caller into revealing details about who they are in real life. But he stopped after his taunting caused one of the scammers to start threatening him personally.

“I probably shouldn’t have, but I recorded two 30-minute conversations with these guys,” Griffin said, acknowledging that maybe it wasn’t such a great idea to antagonize cybercriminals who clearly already knew everything about him. “One guy I talked to about his personal life, and then his friend called me up and said he was going to dox me and do all this other bad stuff. My FBI contact later told me not to talk to these guys anymore.”

Sound advice. So is hanging up whenever anyone calls you about a security problem with one of your accounts. Even security-conscious people tend to underestimate the complex and shifting threat from phone-based phishing scams, but they do so at their peril.

When in doubt: Hang up, look up, and call back. If your response to these types of calls involves anything other than hanging up, researching the correct phone number, and contacting the entity that claims to be calling, you may be setting yourself up for a costly and humbling learning experience.

Understand that your email credentials are more than likely the key to unlocking your entire digital identity. Be sure to use a long, unique passphrase for your email address, and never pick a passphrase that you have ever used anywhere else (not even a variation on an old password).

Finally, it’s also a good idea to take advantage of the strongest multi-factor authentication methods offered. For Gmail/Google accounts, that includes the use of passkeys or physical security keys, which are heavily phishing resistant. For Google users holding measurable sums of cryptocurrency, the most secure option is Google’s free Advanced Protection program, which includes more extensive account security features but also comes with some serious convenience trade-offs.