BEC tools: The 3 techniques most commonly used in BEC attacks

Introduction to BEC

Business email compromise (BEC) remains one of the most damaging threats facing organizations. These attacks succeed because adversaries exploit trust, context, and gaps in business processes rather than relying on malware. BEC blends social engineering, impersonation, and increasingly automated tooling to push fraudulent actions into everyday communication.

Most BEC emails contain no payloads. They rely on clean language, realistic tone, and familiar workflows. Legacy detection tools that depend on signatures or static rules provide limited protection.

This article explains how attackers operate, the BEC tools and techniques they use, and how defenders can detect threats early using behavioral context and adaptive intelligence.

By the end, you will understand the three most common BEC tools attackers rely on and the technologies and strategies that effectively stop them.

Main takeaways

• BEC attacks almost never use malware. They rely on social engineering, trust exploitation, and gaps in financial and operational workflows.
• Threat actors use BEC tools such as domain spoofing, thread hijacking, and credential harvesting kits, often paired with automation and generative AI.
• Traditional SEGs and static rule based systems struggle to detect BEC because they lack behavioral insight and transparency.
• Sublime’s platform blocks BEC by combining adaptive behavioral analysis with explainable AI, supported by agent based systems like their Autonomous Security Analyst (ASA) and Autonomous Detection Engineer (ADÉ).
• Identity controls, MFA, layered business processes, and real time monitoring complement behavioral detection to reduce risk.

What is business email compromise?

Business email compromise is a targeted form of social engineering where attackers impersonate trusted users, internal employees, or vendors to influence financial or access related actions. 

BEC actors craft messages that imitate executives, suppliers, HR teams, or finance personnel. Their goal is to convince a target to authorize a payment, change account information, share sensitive data, or approve access. Because BEC relies on authenticity instead of malware, most emails appear benign and blend into routine communication.

These messages are usually free of links or attachments, with no malware signatures or suspicious URL structures. This allows BEC messages to bypass traditional detection tools.

Why is BEC so hard to stop?

Detecting BEC requires understanding behavior and intent. Static filters focus on content or known malicious indicators, which BEC actors avoid.

BEC attacks rely on trust, not payloads

A typical BEC email may appear to be a routine vendor inquiry, a financial approval request, or a payroll update. With no malware or abnormal formatting, the message appears legitimate.

Targets include finance teams, executives, and vendors

Attackers study a company’s structure and communication patterns. They target roles with authority and access:

• Finance teams approving payments
• Procurement teams processing invoices
• Executives who often delegate work quickly
• HR teams handling payroll and benefits
  
  

Attackers exploit the normal pace and pressure of business, especially during financial reporting cycles.

Most defenses fail because there are no clear detection signals

Effective detection requires understanding what normal communication looks like: tone, timing, thread history, sender relationships, workflows, and vendor behavior. Legacy SEGs and SIEM style rules cannot evaluate these patterns.

The 3 most common BEC tools used by attackers

Attackers use a mix of low cost tools, automation, and social engineering to craft believable messages and infiltrate accounts. These BEC tools enable impersonation, credential theft, and account compromise.

1. Impersonation tactics

Impersonation is central to almost every BEC incident. Common techniques include:

• Email and domain spoofing: When SPF or DKIM are misconfigured or absent, attackers can forge a sender identity.
  
  
• Lookalike domain registration: A single letter change or homoglyph makes a domain appear legitimate.
  
  
• Thread hijacking: Once an account is compromised, attackers reply inside existing conversations, making detection extremely challenging.
  
  
• LLM use for social engineering: Many actors use large language models to generate convincing messages that convey authority and urgency
  
  
• Voice cloning to support vishing: Some BEC operations pair email with AI-generated voice calls to amplify urgency.
  
  

2. Credential theft tools

BEC often begins with stolen credentials rather than spoofing. Common tools include:

• Phishing kits with login pages modeled on Microsoft 365, Google Workspace, and Okta.
• Credential aggregation platforms that combine breach data and stealer logs to build verified username and password lists.
  
  

With valid credentials, attackers can enter mailboxes and escalate to full account compromise.

3. Email account compromise tools

Account compromise gives attackers deeper visibility and control. Common tools include:

• Password cracking and automation frameworks that test large credential sets.
• Social engineering to bypass MFA, including MFA fatigue, real time phishing proxies, or fake IT messages.

Persistent access lets attackers monitor invoicing cycles, payment behavior, and approval processes, making eventual fraud more believable.

Defensive strategies that stop BEC attacks

BEC requires a layered defense across email, identity, behavior, and business workflows.

Use email authentication to block basic spoofing

SPF, DKIM, and DMARC reduce direct spoofing attempts, but they cannot stop lookalike domains or compromised accounts.

Deploy detection that evaluates behavior, not heuristics

Static filters cannot detect subtle behavioral anomalies. Organizations need systems that evaluate relationships, tone shifts, thread manipulation, vendor patterns, and workflow context.

Sublime uses adaptive, explainable models that understand each organization’s communication behavior, making it possible to detect impersonation attempts and thread hijacking.

Implement MFA to prevent unauthorized access

MFA reduces credential based compromise when combined with phishing resistant methods. While not perfect, it forces attackers to adopt more complex social engineering or token theft tactics.

Real-time monitoring accelerates detection

Identity and mailbox behavior monitoring helps surface suspicious activity quickly. This complements email detection by highlighting unusual logins or forwarding rule changes.

Strengthen business process controls

Technical controls cannot stop every attempt. Organizations should enforce:

• Dual authorization for wire transfers
• Out-of-band verification for bank detail changes
• Finance team protocols for supplier validation
• Regular training for high risk roles
  
  

Real world example: $500K vendor payment fraud

Attackers attempted to divert a $500,000 vendor payment by impersonating a supplier with a lookalike domain. They fabricated a thread referencing a legitimate invoice and requested updated ACH details. Because the email contained no payloads and closely mimicked a real workflow, traditional tools would not detect it. Behavioral signals, such as a first time sender and a slightly altered domain, exposed the attack.

Read the full breakdown here.

How Sublime stops BEC in real time

Sublime detects BEC variants that lack payloads or traditional indicators by modeling how each organization communicates.

Adaptive detection that evaluates behavioral anomalies

Sublime analyzes sender behavior, relationships, tone, timing, and thread structure. The system adapts continuously, learning normal communication across roles and vendors.

Explainable decisions with full message lineage

Every detection includes clear reasoning and message lineage. Analysts see exactly which signals contributed to a decision.

Out-of-the-box AI-powered automation for triage and coverage

Sublime works immediately without manual tuning. ADÉ can generate coverage automatically, backtest it, and deploy it safely. ASA classifies and remediates user reported messages with high precision.

These agent based systems reduce manual workload while preserving analyst control.

Stop BEC before it starts with explainable detection from Sublime

BEC continues to evolve as attackers use automation, social engineering, and AI to craft convincing messages.

Organizations need defenses that understand behavior, provide clear reasoning, and adapt in real time. Static systems cannot keep up.

Sublime delivers adaptive, transparent protection inside clean, payload free emails and gives teams the visibility and control they need.

Request a demo to see how Sublime can help your organization reduce BEC risk.

Frequently asked questions about BEC tools and attacks

What are the most common tools used in BEC attacks?

Attackers frequently use domain spoofing, lookalike domains, thread hijacking, phishing kits, and credential harvesting tools. Automation and generative AI often enhance these techniques.

How do attackers bypass traditional email security?

Most BEC emails contain no malicious indicators. Attackers use legitimate infrastructure, compromised accounts, or lookalike domains, which static tools struggle to detect.

How can I tell if an email is part of a BEC attack?

Signals include unusual urgency, unexpected financial requests, tone shifts, domain discrepancies, and workflow changes.

What is the difference between BEC and phishing?

Phishing often relies on malicious links or attachments. BEC focuses on impersonation and fraud using clean messages.

What should organizations do after a BEC attempt?

Teams should review mailbox logs, investigate account activity, check forwarding rules, validate financial workflows, and assess potential secondary compromise.

How does Sublime protect against BEC?

Sublime models communication behavior to detect anomalies that signal impersonation or fraud. Adaptive detection, explainability, and agent based systems like ASA and ADÉ provide real time protection.