Cybercriminals are increasingly using residential IP addresses in business email compromise (BEC) attacks to bypass detection, according to Microsoft. BEC attacks involve fraudulent requests for wire transfers sent from compromised or spoofed email addresses, often resulting in significant financial losses.
By purchasing residential IP services matching the victim’s location, scammers can obscure their login attempts, circumvent detection mechanisms, and conduct further attacks. Microsoft warns organizations to implement strong authentication methods, train employees to recognize fraudulent emails, and employ domain-based message authentication to protect against spoofed emails.
The FBI received nearly 22,000 BEC complaints in 2022, resulting in over $2.7 billion in losses, highlighting the growing prevalence and impact of these attacks.
In a BEC attack, scammers deceive employees responsible for payments by posing as legitimate individuals and requesting transfers to their controlled bank accounts. The new tactic observed involves using residential IP addresses to make the attacks appear locally generated, allowing cybercriminals to obscure their movements and bypass security measures.
Microsoft points out that the use of IP/proxy services, typically employed for research purposes, enables threat actors to gather compromised credentials and scale their attacks.
Microsoft has identified BEC scammers in Asia and an Eastern European country frequently employing this tactic, often leveraging phishing-as-a-service offerings like BulletProftLink. These services utilize blockchain nodes for hosting phishing and BEC sites, making takedown efforts more challenging.
To mitigate the risks of BEC attacks, organizations are advised to implement email rules blocking messages from external sources, enforce strong authentication methods, educate employees about recognizing fraudulent emails, utilize secure email solutions, and deploy domain-based message authentication, reporting, and conformance (DMARC) policies to prevent email spoofing.
Microsoft emphasizes that BEC attempts can take various forms, including phone calls, text messages, and social media interactions, making it crucial to remain vigilant against impersonation and spoofed authentication requests.