Common email security threats in business include phishing attacks, business email compromise, ransomware delivered through email attachments, spoofing, and credential theft through fake login pages. According to the FBI's 2024 Internet Crime Complaint Center report, phishing and spoofing were the top crime type by complaint count, with 193,407 complaints filed that year alone. Email continues to be the single largest gateway for cybercrime, and every business that relies on email communication faces these risks daily. This article breaks down each major email threat, explains how it works, shows the real financial damage it causes, and covers what your team can do to stay protected.

What Are the Major Security Threats Through Email?

The major security threats through email are phishing, business email compromise, ransomware, spoofing, malicious attachments, and credential harvesting through fake login pages. These threats target employees at every level of a company, from entry-level staff to senior executives.

According to the Verizon 2024 Data Breach Investigations Report, 94% of all malware is delivered through email. That single statistic shows why email remains the number one attack method for cybercriminals. It is cheap to launch, easy to scale, and it works because it targets human behavior rather than software weaknesses.

A report by Hornetsecurity that analyzed 55.6 billion emails found that 36.9% of all emails received by businesses in 2024 were unwanted, and 2.3% of those contained malicious content. That adds up to roughly 427.8 million dangerous emails hitting business inboxes in a single year. We see these kinds of threats targeting companies of all sizes, and the damage they cause goes far beyond a single clicked link.

How Does Phishing Work in a Business Setting?

Phishing works in a business setting by using fake emails that impersonate trusted companies, coworkers, or vendors to trick employees into clicking malicious links, downloading harmful attachments, or entering their login credentials on fraudulent websites. According to the Egress 2024 Email Security Risk Report, 94% of organizations fell victim to phishing attacks in the past 12 months, up from 92% the year before.

Phishing is not random anymore. Attackers research their targets on LinkedIn, company websites, and social media. They learn names, job titles, and relationships within a company. Then they craft emails that look and feel like normal business messages. A 2025 study by TitanHQ and Osterman Research found that 64.3% of businesses expect phishing threats to keep rising in the coming years.

The Egress report also found that 89% of phishing emails now involve impersonation tactics. The most commonly impersonated brands include Adobe, DHL, and Microsoft. These emails often tell the recipient that their account is expiring or that they need to verify a payment. Employees who rely on software applications every day are especially vulnerable because these messages blend in with their normal workflow.

New employees face extra risk. Research from Egress shows that new hires receive phishing emails impersonating company VIPs within an average of just three weeks after starting their job. Attackers know that new team members are eager to respond quickly and less likely to question a message from someone who appears to be a boss or manager.

What Is Business Email Compromise and Why Is It So Costly?

Business email compromise, often called BEC, is a type of scam where attackers impersonate executives, vendors, or trusted business partners to trick employees into transferring funds or sharing confidential information. According to the FBI's 2024 IC3 report, BEC losses totaled $2.77 billion across 21,442 reported incidents in 2024 alone.

What makes BEC so dangerous is that these emails usually contain no malicious links or attachments. They rely entirely on trust and social pressure. An employee in accounting might receive what looks like an urgent email from the CEO asking them to wire money to a new vendor. The email address looks correct, the tone is right, and the request seems reasonable. By the time anyone realizes it was a fake, the money is gone.

The FBI reports that BEC scam losses have exceeded $8.5 billion in just the last three years combined (2022 through 2024). According to the Anti-Phishing Working Group, the average wire transfer amount requested in BEC attacks surged to $128,980 in the fourth quarter of 2024, nearly double the $67,145 average from the third quarter. These are not small losses. A single successful BEC attack can cripple a small or mid-sized business financially.

BEC attacks have been reported in all 50 states and 186 countries, according to the FBI's Internet Crime Complaint Center. The Hoxhunt Phishing Trends Report found that BEC attacks accounted for 73% of all reported cyber incidents in 2024. Businesses that invest in managed cybersecurity have stronger defenses against these targeted attacks because their email traffic is actively monitored for suspicious behavior.

How Do Attackers Gain Access for BEC Scams?

Attackers gain access for BEC scams by stealing login credentials through phishing emails, purchasing compromised credentials on the dark web, or using social engineering to manipulate employees into sharing account information. Once they have access to a legitimate email account, they monitor conversations, learn payment patterns, and strike at the right moment.

According to the 2025 Verizon Data Breach Investigations Report, 60% of breaches involved the human element, with phishing accounting for 16% of initial breach vectors and stolen credentials used in 22% of attacks. This means most BEC attacks start with a simple phishing email that captures a password. From there, the attacker has the keys to the entire email account.

What Emails Should You Not Open?

Emails you should not open include messages from unknown senders with unexpected attachments, emails that create a sense of urgency or fear, messages asking you to verify account information through a link, and emails with misspelled domain names or unusual formatting. According to the Hoxhunt Phishing Trends Report, approximately 66% of phishing attempts focus on stealing organizational credentials, while 34% target personal financial information.

Some of the biggest red flags include a sender address that does not match the company it claims to be from, grammar errors in what should be a professional message, and requests for sensitive data like passwords, bank account numbers, or social security numbers. If an email asks you to act fast or threatens consequences, that pressure is almost always a sign that something is wrong.

Businesses that use strong cybersecurity services can filter out many of these dangerous messages before they reach an employee's inbox. But no filter catches everything, which is why every person on your team needs to know what to watch for.

How Does Ransomware Spread Through Email?

Ransomware spreads through email when an employee opens a malicious attachment or clicks a link that downloads malware onto their computer. That malware then encrypts the company's files and demands a ransom payment to unlock them. According to the Verizon 2024 Data Breach Investigations Report, 94% of all malware, including ransomware, is delivered through email.

Ransomware attacks have grown more targeted and more expensive. The average cost of a ransomware attack reached $5.13 million in 2024, according to IBM's Cost of a Data Breach Report. The Verizon 2025 Data Breach Investigations Report found that ransomware was present in 44% of all breaches, a 37% increase compared to the previous year.

Small and mid-sized businesses face the greatest risk. According to Verizon, ransomware was involved in 88% of breaches affecting small and mid-sized businesses in 2024. These companies often lack the advanced security tools and dedicated IT staff needed to detect and stop ransomware before it spreads. The average downtime after an attack is 24 days, which can mean weeks of lost productivity, missed deadlines, and damaged customer trust.

A strong disaster recovery plan is one of the best defenses against ransomware. If your data is backed up regularly and stored securely, you can restore your systems without paying the ransom.

What Types of Attachments Are Used to Deliver Ransomware?

The types of attachments used to deliver ransomware include PDF files, Microsoft Word documents, Excel spreadsheets, ZIP archives, and HTML files. According to the Hoxhunt Phishing Trends Report, PDF attachments were the most common malicious file type, followed by HTML attachments at 5.6% and SVG files at 5%. Microsoft Word documents accounted for 4.4% of malicious attachments.

Only about 10% of malicious attachments contain the actual malware payload directly. The other 90% contain deceptive links that lead to a second step, such as a credential harvesting page or a malware download site. This two-step approach helps attackers avoid detection by basic email filters.

What Is Email Spoofing and How Does It Affect Businesses?

Email spoofing is a technique where attackers forge the sender address on an email to make it look like it came from a trusted source, such as a company executive, a vendor, or a well-known brand. Spoofing is the foundation of most phishing and BEC attacks. According to the FBI's 2024 IC3 report, phishing and spoofing combined were the top crime type by complaint count, totaling 193,407 incidents.

Spoofing works because the basic email protocol (SMTP) does not verify sender identity on its own. Without proper authentication measures in place, anyone can send an email that appears to come from your company's domain. The Egress 2024 Phishing Threat Trends Report found that 84.2% of phishing attacks passed DMARC authentication, one of the most common email security tools, showing that even standard protections are not always enough.

Businesses can fight spoofing by implementing email authentication protocols like SPF, DKIM, and DMARC. According to the UK's National Cyber Security Centre, DMARC has moved from a best practice to a mandatory requirement in many frameworks, including NIST and ISO 27001. We help our clients set up these protections as part of a complete security strategy that covers every layer of their IT environment.

How Likely Is It for Your Email to Get Hacked?

The likelihood of your business email getting hacked is high if you do not have strong security measures in place. According to the Egress 2024 Email Security Risk Report, 94% of organizations experienced phishing attacks in the past year, and 96% of those reported negative consequences. The World Economic Forum estimates that 95% of all cybersecurity issues can be traced to human error, meaning that a single careless click can lead to a compromised account.

Account takeover is one of the top concerns for cybersecurity leaders. Once an attacker gains access to an employee's email, they can use that account to move sideways through the organization, steal data, send phishing emails from a trusted domain, and reset passwords to access other business systems.

Microsoft reports that using multi-factor authentication (MFA) can prevent 99% of credential-based attacks. That one added layer of security makes it dramatically harder for attackers to break into an account, even if they have the password. Every business should require MFA on all email accounts and critical systems. Implementing strong multi-factor authentication is one of the simplest and most effective steps a company can take.

What Are Two Common Email Security Breaches?

Two common email security breaches are credential theft through phishing and unauthorized fund transfers through business email compromise. These two attack types account for billions of dollars in losses every year and affect businesses across every industry.

Credential theft happens when an employee clicks a phishing link and enters their username and password on a fake login page. According to the Hoxhunt Phishing Trends Report, the most popular phishing impersonation targets Microsoft accounts by telling recipients that their multi-factor authentication is expiring. Once the attacker captures the credentials, they have full access to the victim's email and any connected systems.

The second common breach, BEC-related fund transfers, involves attackers impersonating a trusted figure to redirect legitimate payments. IBM's Cost of a Data Breach Report found that breaches initiated through business email compromise cost an average of $4.89 million per incident. These breaches often go undetected for weeks or months because the attacker operates from within a legitimate account.

What Are the Financial Costs of Email Security Threats?

The financial costs of email security threats are massive and continue to grow every year. The FBI's 2024 IC3 report recorded $16.6 billion in total cybercrime losses across the United States, a 33% increase from the previous year. Email-based threats, including phishing, BEC, and data breaches, accounted for more than $4 billion of those losses when combined.

Email Threat TypeReported Losses (2024)Average Cost Per IncidentBusiness Email Compromise$2.77 billion$128,980 (Q4 2024 avg. wire transfer)Phishing/Spoofing$70 million (reported to IC3)$4.88 million (avg. breach cost)Ransomware (email-delivered)$12.4 million (reported to IC3)$5.13 million (avg. breach cost)Personal Data Breaches (email-linked)$1.45 billion$4.44 million (avg. breach cost 2025)

Sources: FBI IC3 2024 Internet Crime Report, Anti-Phishing Working Group Q4 2024 Report, IBM Cost of a Data Breach Report 2024 and 2025

For small businesses, even one successful attack can mean the difference between staying open and shutting down. The IBM 2025 Cost of a Data Breach Report found that the global average cost of a data breach was $4.44 million, while breaches in the United States averaged $10.22 million, an all-time high for any region. Companies with strong cybersecurity audit practices and layered defenses consistently spend less when breaches occur.

What Do Hackers Hate the Most?

Hackers hate multi-factor authentication, well-trained employees, and layered security defenses the most. These three things make it significantly harder for attackers to succeed, even when they manage to steal a password or craft a convincing phishing email.

Microsoft's research shows that MFA blocks 99% of credential-based attacks. When an attacker steals a password but cannot pass the second verification step, the stolen credential becomes useless. The IBM 2025 Cost of a Data Breach Report found that organizations using AI and automation in their security tools saved an average of $1.9 million per breach compared to those without these tools.

Employee training is equally powerful. According to research cited by Kobalt.io, after 12 months of consistent security awareness training, an employee is 70% less likely to click on a phishing email. CISA, the Cybersecurity and Infrastructure Security Agency, recommends ongoing training rather than once-a-year sessions because threats change constantly and employees need regular reminders to stay alert.

How Can Businesses Protect Against Email Security Threats?

Businesses can protect against email security threats by combining strong technical defenses with ongoing employee training. No single tool stops every attack. The most effective approach uses multiple layers of protection that work together. We work with companies across North Alabama to build these layered defenses, and email security is always one of the first things we address.

How to Train Employees on Cyber Hygiene in the Workplace

Training employees on cyber hygiene in the workplace starts with regular, short training sessions that teach staff how to spot phishing emails, verify suspicious requests, and report anything that looks wrong. The World Economic Forum reports that 95% of cybersecurity incidents trace back to human error, which means your people are both your biggest risk and your strongest defense.

Effective training programs include simulated phishing exercises where employees receive fake phishing emails and get immediate feedback when they click. This hands-on approach builds muscle memory and keeps security top of mind. The Egress report found that 88% of organizations conduct security awareness training primarily to meet compliance requirements, but the real value goes far beyond checking a box.

What Technical Defenses Stop Email Threats?

Technical defenses that stop email threats include email filtering and gateway protection, multi-factor authentication, DMARC/SPF/DKIM email authentication, endpoint detection and response (EDR), and regular security monitoring. According to Trend Micro, their email security platform detected and blocked over 57 million high-risk email threats after Microsoft 365 and Google Workspace filters in 2024, a 27% increase over the previous year.

Endpoint detection and response tools provide an additional safety net. If a malicious email gets through the filter and an employee clicks on it, EDR software can detect the unusual behavior and stop the attack before it spreads across the network.

Pairing endpoint protection with a properly configured firewall creates a defense system that catches threats at multiple points. These layers work together so that if one control misses a threat, the next one catches it.

Why Regular Security Audits Matter for Email Protection

Regular security audits matter for email protection because they identify gaps in your defenses before attackers find them. A cybersecurity risk assessment reviews your email configurations, authentication settings, access controls, and employee behavior to find weak spots.

The IBM 2025 Cost of a Data Breach Report found that organizations that identified breaches internally first, before a third party or attacker notification, saved an average of $900,000 per incident. Proactive detection through audits and monitoring pays for itself many times over.

Which Email Is Most Likely Phishing?

The email most likely to be phishing is one that creates urgency, asks you to click a link or open an attachment, comes from a slightly misspelled domain, and requests sensitive information like passwords or payment details. According to the Hornetsecurity Cybersecurity Report, phishing remains the most common form of email attack, responsible for a third of all cyber-attacks in 2024.

Phishing emails are most commonly sent in the morning hours. According to TitanHQ's 2025 research, threat actors time their attacks to catch people checking email on their phones during commutes, where smaller screens make it harder to notice suspicious details. Most phishing emails come from free email providers like Gmail and Yahoo, making them easy to spoof but harder for basic filters to block.

QR code phishing, sometimes called "quishing," emerged as a fast-growing threat in 2024. Attackers embed QR codes in emails that redirect victims to credential-harvesting websites when scanned. According to Trend Micro, URL sandboxing detections surged by 211% in 2024, reflecting attackers' growing reliance on these evasive techniques. Businesses in Huntsville and across the country need to train employees to be cautious with QR codes in unexpected emails.

What Are Some Threats in Business Related to Email?

Some threats in business related to email include insider threats from compromised employee accounts, supply chain attacks through vendor email compromise, data exfiltration through email forwarding rules, and compliance violations caused by exposed sensitive data. These threats extend beyond simple phishing and affect the entire organization.

Supply chain attacks are becoming more common. Attackers compromise a vendor's email account and then send legitimate-looking invoices or payment requests to that vendor's customers. Because the email comes from a real, trusted account, it bypasses most security filters. According to the IBM 2025 Cost of a Data Breach Report, third-party vendor and supply chain compromises were the second most prevalent attack vector, costing an average of $4.91 million per incident.

Data exfiltration through email is another growing concern. Attackers who gain access to a mailbox often set up hidden forwarding rules that silently copy all incoming and outgoing messages to an external address. This allows them to monitor conversations, steal sensitive data, and plan future attacks without the victim ever knowing. Strong network monitoring tools can detect these unusual email behaviors and alert your security team before damage is done.

How Does Email Security Affect Compliance?

Email security directly affects compliance because most regulatory frameworks require businesses to protect sensitive data transmitted through email. Frameworks like HIPAA, PCI DSS, CMMC, NIST, and ISO 27001 all include specific requirements for email security, access controls, encryption, and employee training.

A data breach caused by a phishing email can trigger compliance violations, regulatory fines, and mandatory breach notification requirements. The IBM 2025 report found that breach notification costs averaged $390,000, while the total cost for businesses in the United States hit $10.22 million per incident. Companies that work with government contracts or handle protected health information face even stricter requirements and higher penalties.

Businesses in regulated industries need to treat email security as part of their overall compliance program, not as a separate IT issue. When email protections are built into your compliance framework from the start, you reduce both your security risk and your regulatory exposure at the same time.

Frequently Asked Questions

What Are the 4 Common Security Threats?

The 4 common security threats are phishing, malware (including ransomware), business email compromise, and credential theft. According to the FBI's 2024 IC3 report, these four threat categories collectively accounted for billions of dollars in losses across U.S. businesses. Phishing alone generated 193,407 complaints, making it the most reported cybercrime type in 2024.

What Emails Should You Not Open?

Emails you should not open include messages from unknown senders with attachments, emails pressuring you to act immediately, messages with misspelled sender domains, and any email asking for login credentials or financial information through a link. According to Hornetsecurity's analysis of 55.6 billion emails, 427.8 million emails sent to businesses in 2024 contained malicious content.

How Likely Is It for Your Email to Get Hacked?

Your email is very likely to be targeted. According to the Egress 2024 report, 94% of organizations experienced phishing attacks in the past year, and 96% reported negative fallout from successful attacks. Using multi-factor authentication and strong passwords significantly reduces the chance of a successful account takeover.

Which Email Is Most Likely Phishing?

The email most likely to be phishing is one that impersonates a well-known brand, creates a false sense of urgency, and asks you to click a link or verify your account. According to the Egress Phishing Threat Trends Report, 89% of phishing emails involve impersonation tactics, with Microsoft, Adobe, and DHL being the most commonly spoofed brands.

What Are the Top 10 Security Threats?

The top 10 security threats are phishing, business email compromise, ransomware, credential theft, email spoofing, malicious attachments, QR code phishing, supply chain attacks, insider threats, and data exfiltration. According to the FBI's 2024 IC3 report, total U.S. cybercrime losses reached $16.6 billion, with email-based attacks driving a significant share of that total.

What Do Hackers Hate the Most?

Hackers hate multi-factor authentication, well-trained employees, and security monitoring the most. Microsoft reports that MFA blocks 99% of credential-based attacks. According to IBM, organizations using AI-powered security tools saved $1.9 million per breach on average compared to those without automated defenses.

Which Email Gets Hacked the Least?

The email that gets hacked the least is one protected by multi-factor authentication, strong unique passwords, email authentication protocols like DMARC, and regular security monitoring. No email provider is completely immune to attacks, but accounts with layered security measures are exponentially harder for attackers to breach. According to the Egress report, 84.2% of phishing attacks passed standard DMARC checks, showing that even authentication protocols need to be combined with other defenses for full protection.

Putting It All Together

Email security threats are not going away. They are growing more sophisticated, more targeted, and more expensive every year. The FBI's 2024 data shows $16.6 billion in total cybercrime losses, and email is the delivery method behind the majority of those attacks. Phishing, business email compromise, ransomware, and spoofing all exploit the same vulnerability: human trust.

The good news is that every one of these threats is preventable with the right combination of technology, training, and ongoing vigilance. Multi-factor authentication alone stops 99% of credential attacks. Regular training makes employees 70% less likely to click on phishing links. Layered defenses like email filtering, EDR, firewalls, and security monitoring catch what slips through the cracks.

If you want to strengthen your email security and protect your business from these threats, Interweave Technologies is here to help. You can reach our team at (256) 837-2300 or visit our contact page to schedule a conversation about your security needs.

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