Microsoft Detects Growing Use of File Hosting Services in Business Email Compromise Attacks
Oct 09, 2024
Enterprise Security / Identity Theft
Microsoft is warning of cyber attack campaigns that abuse legitimate file hosting services such as SharePoint, OneDrive, and Dropbox that are widely used in enterprise environments as a defense evasion tactic. The end goal of the campaigns are broad and varied, allowing threat actors to compromise identities and devices and conduct business email compromise ( BEC ) attacks, which ultimately result in financial fraud, data exfiltration, and lateral movement to other endpoints. The weaponization of legitimate internet services (LIS) is an increasingly popular risk vector adopted by adversaries to blend in with legitimate network traffic in a manner such that it often bypasses traditional security defenses and complicates attribution efforts. The approach is also called living-off-trusted-sites (LOTS), as it leverages the trust and familiarity of these services to sidestep email security guardrails and deliver malware. Microsoft said it has been observing a new trend in phishing c...