New BEC cyberattacks use phishing with a official Dropbox hyperlink as a lure for malware and credentials theft.
Risk actors have added a brand new wrinkle to conventional enterprise e mail compromise cyberattacks. Name it BEC 3.0 — phishing assaults that bury the hook in official internet providers like Dropbox.
Avanan, a unit of Verify Level Software program, has tracked a latest instance of this assault household, by which hackers created free Dropbox accounts to seize credentials or cover malware in legitimate-looking, contextually related paperwork resembling potential staff’ resumes.
The assault, the safety agency found, began with the actors sharing a PDF of somebody’s resume by way of Dropbox. The goal can’t view the doc until they Add To Dropbox. The hyperlink from Dropbox appeared official, making the exploit tougher to identify.
The phishing exploit includes these steps:
- First, a person clicks the hyperlink in a official notification from Dropbox to a resume and accesses a web page hosted on the file-sharing service.
- The person should then enter their e mail account and password to view the doc. Which means the menace actors have entry to e mail addresses and passwords.
On this web page hosted on Dropbox, customers are requested to enter their e mail account and password to view the doc, giving menace actors person credentials.
As soon as a person enters their credentials, they’re directed to a faux Microsoft OneDrive hyperlink. By clicking on the hyperlink, customers are given a malicious obtain.
“We’ve seen hackers do numerous BEC assaults,” Jeremy Fuchs, a cybersecurity researcher/analyst at Avanan, stated in a report on the assault. “These assaults have a number of variations, however typically they attempt to spoof an govt or accomplice to get an finish person to do one thing they don’t wish to do (like pay an bill to the flawed place),” he stated.
SEE: One other hide-the-malware assault focuses on DNS (TechRepublic)
“Leveraging official web sites to host malicious content material is a surefire strategy to get into the inbox,” he stated. “Most safety providers will take a look at the sender — on this case, Dropbox — and see that it’s official and settle for the message. That’s as a result of it’s official,” he added.
Avanan stated stopping these stealth assaults requires quite a few defensive steps, together with scanning for malicious information in Dropbox and hyperlinks in paperwork, in addition to changing hyperlinks within the e mail physique and inside attachments. The important thing to training towards these social engineering assaults is context, in line with Fuchs: “Are resumes sometimes despatched by way of Dropbox? If not, it could be a cause to contact the unique sender and double-check. If they’re, take it one step additional. If you log into Dropbox, do I’ve to log in once more with my e mail?”
Avanan stated the researchers reached out to Dropbox on Might 15 to tell them of this assault and analysis.
Linktree additionally used to seize credentials
Earlier this month, Avanan found an identical hack utilizing the social media reference touchdown web page Linktree, which is hosted on websites like Instagram and TikTok. Just like the Dropbox assaults, hackers created official Linktree pages to host malicious URLs to reap credentials.
The attackers despatched targets spoofed Microsoft OneDrive or SharePoint notifications {that a} file has been shared with them, instructing them to open the file, in line with Avanan. In the end, the person is redirected to a faux Workplace 365 login web page, the place they’re requested to enter their credentials, the place their credentials are stolen.
“[Users] ought to assume: Why would this individual ship me a doc by way of Linktree? Most definitely, that wouldn’t be the case. That’s all part of safety consciousness — understanding if an e mail or course of appears logical,” stated Fuchs.
In these circumstances, the agency means that recipients:
- All the time test the sender’s tackle earlier than replying to an e mail.
- Cease and assume if the medium getting used to ship a file is typical.
- When logging right into a web page, double-check the URL to see if it’s Microsoft or one other official web site.
BEC assaults utilizing official websites could escalate this yr
Fuchs stated there are not any apparent visible cues to tip off assault recipients to BEC exploits. “Though should you have been to signal into the Dropbox web page, you’d see that there’s a OneDrive emblem and hyperlink,” he stated. “Eagle-eyed customers ought to discover that discrepancy and assume—why would there be two competing providers on one web page?,” he added.
He predicted that these assaults will escalate. “Any well-liked service that’s legit can probably be used as a car to ship the sort of malicious exercise. That’s why we count on it to take off within the close to future,” he stated, including that the exploit has been used tens of hundreds of occasions. “We imagine this can actually take off in quantity within the second half of the yr,” he stated.
