A newly discovered Vietnamese-linked operation has been observed using a Google AppSheet as a "phishing relay" to distribute phishing emails with an aim to compromise Facebook accounts.
The activity has been codenamed AccountDumpling by Guardio, with the scheme selling the stolen accounts back through an illicit storefront run by the threat actors. In all, roughly 30,000 Facebook accounts are estimated to have been hacked as part of the campaign.
"What we found wasn't a single phishing kit," security researcher Shaked Chen wrote in a report shared with The Hacker News. "It was a living operation with real-time operator panels, advanced evasion, continuous evolution and a criminal-commercial loop that quietly feeds on the same accounts it helps steal back."
The findings are just the latest example of how Vietnamese threat actors continue to embrace various tactics to gain unauthorized access to victims' Facebook accounts, which are then sold on underground ecosystems for monetary gain.
The starting point of the latest attacks is a phishing email targeting Facebook Business account owners, claiming to be from Meta Support and urging them to submit an appeal, or risk getting their account permanently deleted. The emails are sent from a Google AppSheet address ("noreply@appsheet.com"), allowing them to bypass spam filters.
