5 Advanced Email Threats You Need to Watch Out for in 2025

Cybercriminals, ranging from politically driven hackers to financially motivated criminal organizations, constantly seek to exploit a variety of attack surfaces. They target critical software vulnerabilities, such as those recently patched in Microsoft Windows and Google Chrome, take advantage of firmware exploits requiring access to devices, and even bypass session cookie two-factor authentication. However, the most common—and by far the easiest—method for these attackers remains through the front door of your email inbox. Security analysts have issued a new warning about five advanced email-based attacks that everyone should be aware of, whether you’re an individual or part of a business.

From individual users to multinational corporations, everyone is at risk of cyberattack. According to a recent report by threat intelligence firm Abnormal Security, email remains the primary vector for most cybercriminals. The analysis highlights that understanding this attack surface is key to protecting yourself from digital threats. Email’s widespread use and inherent trustworthiness make it the perfect tool for attackers to exploit. “The effectiveness of these attacks lies in their ability to manipulate trust,” warned the report published on December 11. Attackers often impersonate familiar contacts, exploit compromised accounts, or weaponize well-known platforms to gain access to sensitive information. Understanding how attackers use these methods to breach defenses is vital for preparing against such threats.

Abnormal Security’s team analyzed real-world email-based attacks from 2024 and identified five primary threat types that are likely to escalate as we approach 2025. These include phishing tactics targeting cryptocurrency users, file-sharing phishing, multichannel phishing, business email compromise (BEC), and email account takeovers. Cryptocurrency, due to its decentralized nature and fast, irreversible transactions, offers cybercriminals a prime opportunity for exploitation. Many individuals, particularly those less experienced with the financial landscape, are drawn to crypto’s promise of large profits without fully understanding the risks involved. This combination of factors has made cryptocurrency a major theme for phishing attacks. Cybercriminals exploit this lack of understanding, leading to a rise in email scams offering fraudulent investment opportunities or fake crypto giveaways. Abnormal Security’s report emphasizes the importance of caution when dealing with unsolicited emails related to cryptocurrency. Attackers often use these emails to steal funds or personal information. With the continued rise in cryptocurrency’s popularity, these scams are expected to intensify in the coming year.

Another growing threat identified by Abnormal Security is file-sharing phishing. Attackers use legitimate file-hosting or e-signature platforms, such as Dropbox, ShareFile, and DocuSign, to deliver phishing attacks. These platforms often offer free registration or trial periods and are API-enabled, which makes it easier for cybercriminals to send phishing emails at scale. The report notes a staggering 350% increase in file-sharing phishing attacks from June 2023 to June 2024. In these attacks, the malicious payload isn’t contained in a simple link within the email; instead, the victim is encouraged to open a document hosted on a genuine file-sharing service. Once opened, the document may contain malware or prompts for sensitive information, making this a particularly insidious threat.

Multichannel phishing is an evolution of traditional phishing tactics. Instead of relying solely on email, attackers use multiple communication channels to manipulate their victims. The process typically begins with an email that leads the victim to other platforms, such as text messages, phone calls, or third-party messaging apps like WhatsApp and Telegram. This method enhances the effectiveness of the attack by leveraging the trust victims have in the communication channels. “Unlike traditional phishing,” the report explains, “which relies exclusively on email, multichannel campaigns are more sophisticated and can initiate contact through various channels, making them harder to spot and block.”

Business Email Compromise (BEC) attacks remain one of the most financially damaging email threats. Cybercriminals impersonate trusted individuals or business partners, often leveraging the implicit trust built into business relationships. The goal is to trick recipients into disclosing sensitive information, authorizing fraudulent financial transactions, or engaging in other harmful activities. Abnormal Security points out that BEC attacks have become more sophisticated, thanks in part to the rise of artificial intelligence (AI). AI tools can analyze vast amounts of data from social media, online activities, and past interactions to create hyper-personalized messages that closely mimic the writing style of the impersonated individual. This AI-powered approach makes it easier for attackers to deceive even the most cautious targets.

The final threat highlighted in the report is email account takeover, which is considered one of the most dangerous forms of email-based attacks. These attacks can be initiated using various techniques, including phishing, social engineering, password stuffing, and session hijacking through authentication token theft or forgery. Once a cybercriminal has control of an email account, they can use the account’s established reputation to carry out malicious activities, making it harder for security systems to detect the attack. The report underscores that email account takeovers are particularly insidious because they allow attackers to bypass many common security measures, such as two-factor authentication, and carry out their activities undetected.

While there are several ways to mitigate the risk of email-based attacks, from awareness campaigns to advanced technological defenses, the report highlights that these methods are not foolproof. The fact that we’re still discussing these threats today indicates that current defenses aren’t enough to prevent all attacks. So, what can be done to stop the growing wave of phishing and other email-based threats? The key to combating these attacks lies in constant vigilance. Users must be educated about the latest phishing tactics, encourage cautious handling of unsolicited emails, and adopt better security practices. This includes enabling two-factor authentication where possible, verifying unexpected requests through secondary channels, and keeping software up to date. Additionally, businesses must invest in security measures such as AI-based email filtering and advanced threat detection tools to spot suspicious activity more effectively.

In conclusion, email remains one of the most vulnerable entry points for cybercriminals, but by understanding the evolving threats and taking proactive steps, individuals and organizations can better protect themselves from these advanced email attacks. The advice is clear: stay informed, stay cautious, and keep your defenses up as cybercriminals become more sophisticated with their methods.