Trusted Cloud Services Used in Large-Scale Facebook and Microsoft Phishing Campaigns
Researchers reported two large phishing operations that abused trusted platforms to improve delivery and evade defenses. Guardio said the AccountDumpling campaign used Google AppSheet to send emails from legitimate Google infrastructure while impersonating Meta Support and recruiters, luring Facebook Business users with fake account disablement notices, copyright complaints, and job offers. The operation compromised about 30,000 Facebook accounts across roughly 50 countries, stealing credentials, 2FA codes, personal data, and government ID images; the stolen information was often funneled through Telegram channels, and the hijacked accounts were later sold or monetized through fraudulent advertising and scams. Evidence in generated PDF metadata linked the activity to Vietnam-based operators, including an individual identified as PHẠM TÀI TÂN.
Microsoft separately disclosed an adversary-in-the-middle phishing campaign that used fake workplace compliance notices to target more than 35,000 users at 13,000 organizations in 26 countries, with most activity concentrated in the United States. Attackers posed as internal HR and compliance teams, sent urgent messages with attached PDFs, and pushed victims through redirects, CAPTCHA checks, and a counterfeit Microsoft sign-in page designed to steal session tokens rather than just passwords, allowing account access without the victim's second factor. The incidents show how attackers are increasingly relying on legitimate cloud services and convincing enterprise-themed lures to bypass spam controls, defeat traditional authentication protections, and accelerate account takeover at scale.
Timeline
May 5, 2026
Microsoft discloses findings on AiTM compliance-notice campaign
Microsoft Defender Research publicly detailed the April phishing campaign, explaining its use of PDFs, redirects, CAPTCHA checks, and fake Microsoft sign-in pages to capture session tokens and bypass passwords and second-factor prompts. Microsoft also issued mitigations including phishing-resistant MFA, Defender for Office 365 protections, and user awareness measures.
May 1, 2026
Guardio links AccountDumpling to Vietnamese operators
Guardio reported evidence tying the AccountDumpling operation to Vietnamese threat actors, including metadata from generated PDFs and infrastructure associated with an individual named PHẠM TÀI TÂN. The reporting also described exfiltration via Telegram channels and the resale of hijacked Facebook accounts on illicit marketplaces.
May 1, 2026
AccountDumpling phishing campaign compromises Facebook accounts
An ongoing phishing operation dubbed AccountDumpling targeted Facebook Business and advertiser account owners by impersonating Meta support and recruiters, abusing trusted services including Google AppSheet to deliver lures and harvest credentials. The campaign reportedly compromised about 30,000 Facebook accounts across roughly 50 countries, with stolen data and access monetized through scams, ad abuse, and illicit account sales.
Apr 14, 2026
Fake compliance notice phishing campaign runs in waves
A separate adversary-in-the-middle phishing campaign operated from April 14 to April 16, 2026, using fake workplace compliance and HR notices to steal Microsoft account session tokens. It targeted more than 35,000 users across 13,000 organizations in 26 countries, primarily in the United States.
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1 months ago
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1 months ago
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