Business email compromise (BEC) and vendor email compromise (VEC) attacks can result in huge financial losses that can prove catastrophic for businesses, and these attacks are being conducted with increasing regularity.

BEC and VEC attacks have their roots in phishing and often involve phishing as the first stage of the attack. These attacks involve impersonation of a trusted person through spoofed or compromised email accounts. The attacker then tricks the targeted individual into disclosing sensitive information or making a fraudulent wire transfer. In the case of the latter, the losses can be considerable. A company employee at Orion, a Luxembourg carbon black supplier, resulted in fraudulent transfers of $60 million. The employee was tricked into believing he was conversing with a trusted vendor and made multiple fraudulent transfers to the attacker’s account.

BEC and VEC attacks are among the most difficult email threats to detect, as they often use legitimate, trusted email accounts so the recipient of the email is unaware that they are conversing with a scammer. Since the attacker often has access to emails, they will be aware of confidential information that no other individual other than the genuine account holder should know. The attacker can also check past emails between the account holder and the victim and can mimic the writing style of the account holder. These attacks can be almost impossible for humans to distinguish from genuine communications. Scammers often reply to existing email threads, which makes these scams even more believable.

BEC/VEC scammers are increasingly turning to AI tools to improve their attacks and AI tools make these scams even harder for humans and email security solutions to identify.  AI tools can be fed past emails between two individuals and told to create a new email by mimicking the writing style, resulting in perfect emails that could fool even the most security-aware individual.

Some of the most convincing VEC attacks involve the use of compromised email accounts. The attacker gains access to the account through phishing or stolen credentials and searches through the account for information of interest that can be used in the scam. By searching through sent and stored emails, they can identify the vendor’s clients and identify targets. They are then sent payment requests for fake invoices, or requests are made to change the bank account information for genuine upcoming payments.

Due to the difficulty of identifying these threats, a variety of measures should be implemented to improve defenses, including administrative and technical controls, as well as employee training. In order to beat AI tools, network defenders need to adopt AI themselves, and should implement a spam filter with AI and machine learning capabilities, such as the SpamTitan cloud-based spam filtering service.

SpamTitan analyzes the genuine emails received by the company to create a baseline against which other emails can be measured. Through machine learning, Bayesian analysis, and other content checks, SpamTitan is able to identify the signs of BEC/VEC and alert end users when emails deviate from the norm. An anti-phishing solution is also strongly recommended to protect accounts against initial compromise and to raise awareness of potential threats. PhishTitan from TitanHQ incorporates cutting-edge threat detection with email banners warning about external emails and other threats and allows IT teams to rapidly remediate any attacks in progress.

Security awareness training is essential for raising awareness of the threat of BEC and VEC attacks. Since these scams target executives, IT, and HR staff, training for those users is vital. They should be made aware of the threat, taught how to identify these scams, and the actions to take when a potentially malicious message is received. With the SafeTitan security awareness training program it is easy to create training courses and tailor the content to cover threats each user group is likely to encounter to ensure the training is laser-focused on the most pertinent threats.

While spam email filtering and security awareness training are the most important measures to implement, it is also important to strengthen defenses against phishing through the adoption of multi-factor authentication on all email accounts, to prevent initial compromise. Administrative controls should also be considered, such as requiring employees to verify any high-risk actions, such as changes to bank accounts or payment methods, and maintaining a contact list of verified contact information to allow phone verification of any high-risk change. This two-step verification method can protect against all BEC/VEC attacks and prevent fraudulent payments.

Jennifer Marsh

With a background in software engineering, Jennifer Marsh has a passion for hacking and researching the latest cybersecurity trends. Jennifer has contributed to TechCrunch, Microsoft, IBM, Adobe, CloudLinux, and IBM. When Jennifer is not programming for her latest personal development project or researching the latest cybersecurity trends, she spends time fostering Corgis.