Business Email Compromise remains one of the most effective and damaging cybercrime techniques in use today. Unlike ransomware or malware-driven attacks, BEC does not rely on exploits or malicious payloads. It relies on people, trust, and routine business processes. That is precisely why it continues to succeed, even in organisations with mature technical security controls.
Modern BEC attacks have evolved well beyond simple phishing emails. Attackers now target identities, hijack live sessions, bypass multi-factor authentication, and quietly persist inside mailboxes for weeks or months. In this environment, traditional awareness training is no longer sufficient. What is required is a managed, adaptive approach to security awareness that evolves alongside attacker behaviour and actively reduces risk.
At its core, a BEC attack is an identity-led intrusion designed to manipulate legitimate business communications. The attacker’s objective is rarely immediate theft. Instead, they seek access to trusted inboxes, internal conversations, and financial workflows. With gen AI tools attackers can make phishing emails and communications look professional and can use deepfakes to dupe individuals.
Once inside, attackers observe how the organisation operates. They learn who approves payments, how suppliers communicate, how executives write emails, and which processes are followed during routine transactions. The eventual fraud is often subtle, well-timed, and convincingly legitimate.
Because no malware is involved and communications appear authentic, BEC frequently bypasses traditional email security tools. This is why human behaviour and awareness play such a decisive role in stopping these attacks early.
Today’s BEC investigations increasingly begin with session and token theft rather than stolen passwords. Adversary-in-the-Middle techniques allow attackers to intercept authentication flows in real time, capturing valid session tokens after a user successfully logs in. This enables them to bypass MFA entirely without triggering obvious alerts.
Once authenticated, attackers operate as the user. They access mailboxes, cloud services, collaboration tools, and file shares without needing to reauthenticate. This shift has made token and session theft the primary driver behind modern BEC compromises.
From there, attackers establish persistence. Mailbox rules are created to hide security alerts or divert replies. OAuth tokens are abused to maintain access even after passwords are changed. In some cases, dormant or lightly monitored accounts are used as staging points to expand access further.
These techniques allow attackers to remain invisible while they map internal relationships and plan their next move.
BEC attackers rarely rush. Stealth is their advantage. By remaining quiet, they reduce the risk of detection while gathering intelligence.
Access brokers and compromised suppliers play an increasing role in this stage. An attacker may gain initial access through a third party, a supplier mailbox, or a forgotten account that still has access to shared systems. From there, they pivot laterally, following trust chains rather than technical vulnerabilities.
This lateral movement is social rather than technical. Attackers observe how people communicate, who trusts whom, and where authority lies. They then exploit those relationships to escalate access or initiate fraudulent requests.
Without visibility into behavioural anomalies and user-reported concerns, these intrusions often go unnoticed until financial damage has already occurred.
One of the most overlooked aspects of BEC defence is recognising the early indicators of compromise. Long before money moves, there are behavioural signals that something is wrong.
These can include unusual login locations, changes to mailbox rules, unexpected consent to OAuth applications, or subtle shifts in email tone and timing. Attackers may suddenly show interest in finance conversations, supplier details, or approval workflows they previously ignored.
Managed Security Awareness plays a critical role here. When users are trained to recognise these signals and encouraged to report anything unusual, detection moves from the SOC alone to the entire organisation. Early reporting often turns what could have been a major financial incident into a contained security event.
Defending against BEC requires a layered approach that combines identity hardening, detection, response, and awareness.
Strong Conditional Access policies should be enforced to reduce session abuse, including location controls, device trust, and continuous authentication checks. Identity protections must extend beyond passwords and MFA to include token monitoring and session risk.
Email security controls should focus on behavioural analysis rather than solely scanning for malicious links or attachments. BEC emails are often clean, context-aware, and socially engineered.
From a security operations perspective, SOC teams must tune detection logic to identify identity-based attacks, not just malware. Incident response workflows should be designed to handle mailbox compromise, token revocation, and rapid containment of trusted accounts.
However, none of these measures are fully effective without informed users.
Business Email Compromise attacks succeed by abusing trust. Once attackers gain access to a legitimate account, traditional security models often treat that user and session as safe. Zero Trust challenges this assumption by operating on the principle that compromise should always be expected.
For BEC defence, this is critical. Modern attacks frequently rely on session hijacking and token theft, allowing attackers to bypass MFA and operate as trusted users. Zero Trust limits the damage by continuously verifying identity, device posture, location, and behaviour, even after login.
Strong Conditional Access, least-privilege access, and continuous session evaluation make it harder for attackers to persist, pivot, or access sensitive financial workflows. Lateral movement is restricted, and suspicious behaviour is surfaced sooner. However, it is no silver bullet.
Business Email Compromise attacks are a sophisticated form of social engineering that often bypass standard tools because they don’t use obvious malware or malicious links. Tackling these attacks effectively requires a whole-of-organisation approach that strengthens identity and behavioural visibility, reinforces technical controls, and builds human resilience.
BEC defence starts with understanding how identities and accounts behave. Integrity360’s Managed Detection & Response (MDR) and Managed SIEM services provide continuous 24/7 monitoring of networks, endpoints, cloud workloads, and logs to detect unusual activity — including abnormal logins, mailbox rule changes, or OAuth consent anomalies that often signal compromised accounts. These telemetry sources help identify suspicious patterns early, long before money moves.
Modern threats move fast, and AI-assisted tools help surface subtle deviations that might indicate a BEC attack. Integrity360’s MDR and CyberFire MDR leverage advanced analytics and behaviour profiling to detect identity misuse, while experienced security analysts validate, prioritise, and respond to alerts — reducing false positives and improving detection outcomes.
When an account behaves unexpectedly, speed is critical. Integrity360’s MDR delivers automated detection and rapid incident response across the estate. With expert analysts operating out of multiple Security Operations Centres, suspicious activity can be contained swiftly — including session isolation, token revocation, and remediation of compromised credentials — reducing dwell time and stopping attackers before they escalate BEC tactics.
Attacker behaviour often relies on social cues, trust exploitation, or manipulation of internal processes. Integrity360’s Managed Security Awareness service goes far beyond generic e-learning, designing ongoing, tailored campaigns and simulations that reflect real BEC scenarios. These programmes help employees — especially those in high-risk roles such as finance or executive support — recognise sophisticated social engineering and report potential issues early, turning the organisation’s workforce into an active line of defence.
Integrity360’s managed Microsoft security services help organisations get far more value and protection from their existing Microsoft investments, particularly Microsoft Entra ID, Microsoft Defender, and Microsoft Sentinel. We support organisations in configuring and optimising Conditional Access policies, identity protection controls, and MFA enforcement to reduce the risk of session hijacking and token abuse commonly used in modern BEC attacks.
Identity abuse sits at the heart of BEC attacks. Integrity360 also offers Managed Identity Security services and guidance through its “Defending Identities” resources to help organisations implement strong conditional access, token monitoring, and identity hygiene best practices that make adversary-in-the-middle techniques and session hijacks more difficult to achieve.
Good cyber hygiene reduces secondary risk. Integrity360 supports ongoing patching, secure configuration, and continuous threat exposure management to ensure that defensive layers such as email filtering, endpoint hardening, and network segmentation are optimised. These measures not only reduce the likelihood of BEC escalation but also support rapid containment when issues appear.
By combining enhanced visibility, expert-validated detection, automated response, and a managed awareness programme, organisations with Integrity360 can significantly improve their defence against BEC attacks. This layered approach addresses both the technical signals attackers emit and the human behaviours they target. If you’d like to learn more about how Integrity360s experts can help your organisation get in touch.