How To Prevent Phishing: Essential Strategies for Businesses

Cybersecurity risks are growing in both scale and sophistication. Yet while hacking groups and ransomware gangs are always developing new and more sophisticated ways of targeting businesses, one tried and tested solution continues to bear fruit: phishing.

Email channels, in particular, remain one of the most persistent and effective ways of gaining entry to a network, whether this is through delivering malicious links, harvesting login credentials or installing malware. Once inside, attackers can move laterally through a network, disrupt operations and exfiltrate sensitive data.

However, just because phishing has been around for a while, this doesn’t mean it’s been standing still. Modern attacks are more targeted and convincing than ever, increasingly driven by AI and delivered at scale. Protecting against them demands more than just filters and firewalls. Businesses must combine smart technology with a strong culture of security. That means empowering employees to recognize and respond to threats in real-time.

Phishing is a form of social engineering in which attackers impersonate legitimate entities to deceive users into sharing sensitive information or downloading malicious content. Email is the most common method for sending these communications, but they can also use messaging apps, voice services, social media and collaboration tools. Once a user clicks a link or opens a compromised attachment, the attacker can steal credentials, install malware or gain entry into the wider network.

Phishing remains one of the most common and damaging cyberattack vectors. According to the UK government’s 2025 cybersecurity breaches survey, 85 percent of businesses in the country experienced a phishing attack in the last 12 months, making this the most prevalent and disruptive type of breach. The study also noted they are among the most time-consuming problems to address due to their volume and the need for investigation and staff training.

The consequences of a successful phishing attack can be severe, ranging from ransomware deployment and data theft to financial fraud and prolonged operational disruption. It may only take one mistake for even the largest organizations to fall victim. For example, in 2023, the high-profile breach of MGM Resorts was reported to have been traced back to a social engineering attack that started with a phishing call. The breach ultimately cost the company around $100 million, illustrating the severe damage these entry methods can lead to.

“Phishing remains one of the most effective ways for attackers to gain access to sensitive information because it targets people, not just technology. The reality is that no organization is immune, as even the most tech savvy employees and security-conscious teams can be deceived by a well-crafted message. The best defense is layered: combine education and awareness with technology that mitigates the risk of data exfiltration if an attack succeeds.”

• Dr Darren Williams, Founder and CEO, BlackFog.

Phishing attacks come in many forms. While they all aim to deceive individuals into handing over sensitive information or access, the tactics used can vary widely depending on the attacker’s goals, target and level of sophistication. Understanding the different types is essential for both identifying threats and implementing effective defense strategies. Some of the most common forms of phishing attack seen in enterprise environments today include:

• Spear phishing: These are highly targeted attacks directed at a specific individual or team, often using personal or job-related details to appear credible.
• Whaling: A form of spear phishing that targets senior executives by impersonating trusted sources to authorize payments or share confidential data.
• Voice phishing (vishing): A phone-based method where attackers pose as IT, banks or colleagues to extract login details or trick users into installing malicious software.
• Smishing: This refers to phishing delivered via SMS or messaging apps, typically containing malicious links or fake alerts from banks, delivery services or internal systems.
• Clone phishing: A legitimate email is duplicated, with malicious links or attachments replacing the originals, before being re-sent to the target to appear as a follow-up.

Early detection is one of the most effective ways to prevent phishing attacks from succeeding. Even with strong filters and endpoint protections in place, phishing emails can still reach users’ inboxes. That’s why training staff to recognize the signs of suspicious communication is critical.

Well-informed employees act as a vital human firewall, helping prevent threats before they escalate into full-scale incidents. Common red flags to watch for include:

• Spelling or grammar errors: Phishing messages often contain awkward language or mistakes not typical of professional communication. However, this is not always a telltale sign, as today’s AI-powered messages may be more accurate and well-presented than in the past.
• Hidden or suspicious URLs: Hovering over links can reveal mismatched or misspelled web addresses designed to mimic legitimate domains. Staff members need to be alert to subtle changes or hidden redirects that can mask the true destination of a link.
• A sense of urgency: Language urging immediate action, such as “your account will be locked”, is a common manipulation tactic, especially when threat actors are impersonating senior members of staff. This often pressures users into acting without taking the time to fully check the veracity of the message.
• Unexpected attachments: Files from unknown senders or messages that don’t typically include attachments should raise suspicion.
• Unusual requests: Emails asking for sensitive information, financial transfers or credential resets that are unexpected, out of context or outside a user’s typical activities are likely fraudulent.

Preventing phishing requires a multi-layered defense that combines technology, training and proactive security. Employees are the first line of contact, so regular education on spotting suspicious messages and verifying sources is vital. Yet vigilance alone isn’t enough.

Email security and anti-phishing tools – from spam filters to sandboxing and domain protection – help block threats before they reach users, while secondary defense layers including endpoint monitoring, network segmentation and anti data exfiltration (ADX) ensure attackers can’t move freely or steal data if a breach occurs.

Good anti-phishing practices fall into three key pillars: user behavior; good digital hygiene and security best practices; and wider network protections. Below are 12 essential elements within these categories.

User behavior is a critical line of defense against phishing, especially as attackers become more targeted and convincing. Building a culture of awareness starts with practical habits, as well as empowering staff to question suspicious communications and giving them a process for reporting threats helps prevent phishing before it begins. Key messaging to share with staff include:

1. Think before you click: Always hover over links before clicking. Watch for strange spellings, subdomains or URLs that don’t match the sender.
2. Verify the sender: Check the email address carefully. Threat actors often spoof names, but it’s harder to hide the true address the message originates from.
3. Don’t download untrusted attachments: Unless you were expecting a file – and can verify the sender – treat all attachments with caution.
4. Pause when emails feel urgent or threatening: Phishing messages often use panic or authority to override judgment. If something feels off, slow down and escalate through official channels.

While individual awareness is essential, businesses must also implement the right technical controls on all user accounts and devices to reinforce secure habits. These tools form the foundation of digital hygiene across your environment. Important factors within this pillar are:

5. Enable multi-factor authentication: This ensures that even if credentials are compromised in a phishing attack, threat actors can’t log in without a second verification method.
6. Use strong, unique passwords: Avoid password reuse across services – especially between users’ company and personal accounts. A password manager helps employees generate and store unique, complex logins securely.
7. Keep software and devices updated: Phishing emails often deliver malicious links or attachments designed to exploit outdated software – regular updates prevent this.
8. Turn on anti-phishing features: Platforms like Microsoft 365 and Google Workspace include anti-phishing filters, link scanning and warning banners. It’s important these are properly configured and maintained.

For phishing prevention to be truly effective, organizations must also adopt a layered security strategy. This means implementing controls that operate beyond the inbox at both the network and policy level, ensuring that even if users do fall victim, attackers will not be able to penetrate deeper into the network to cause disruption or exfiltrate data.

9. Use email authentication protocols: Tools like SPF, DKIM and DMARC prevent attackers from sending spoofed emails that look like they come from your domain, reducing the risk of impersonation.
10. Run phishing simulation training: Simulated attacks test staff readiness in real-world conditions, showing who may need further training and reinforcing safe behavior.
11. Secure your Wi-Fi and network devices: Unsecured routers or flat networks make it easier for attackers to move laterally once phishing gives them an entry point. Strong encryption and segmentation reduce this risk.
12. Deploy endpoint protection and monitoring tools: Even if phishing succeeds, solutions like endpoint detection and ADX can spot and block suspicious activity to prevent attackers from stealing data or escalating their access.

When phishing slips past the front line, these back-end defenses are what stop a minor mistake from becoming a major breach.

The most effective way to prevent phishing is to block malicious messages before they ever reach an inbox. This requires dedicated technical solutions that detect, block and neutralize threats at the earliest stage of delivery. The following tools form a critical first line of defense:

• Secure email gateways: These scan inbound and outbound emails for malware, suspicious links and spoofed domains, quarantining dangerous content before it reaches users.
• Anti-phishing filters: Built into platforms like Microsoft 365 and Google Workspace, these use AI and threat databases to detect phishing patterns and block suspicious emails in real-time.
• DNS filtering: Prevents users from accessing malicious websites by blocking connections at the DNS level, ensuring protection even if they click on a phishing link.
• Attachment sandboxing: Opens attachments in isolated environments to detect malicious behavior before delivery.
• Email authentication protocols: These verify sender legitimacy, protecting against spoofed or impersonated domains.

Combined, these tools reduce the phishing load on users and prevent threats before human error can occur.

While the above technologies are effective in guarding against phishing threats when used correctly, they aren’t foolproof. Sophisticated attacks can sometimes find a way to evade defenses, while related social engineering threats like vishing avoid the inbox altogether. In such cases, your employees are your next line of defense.

IT and security teams must therefore deliver regular, practical training that helps employees understand how phishing works, what red flags to look for and how to respond when something feels suspicious. This should include guidance on verifying senders, spotting malicious links and knowing when to escalate concerns.

Equally important is making sure these lessons stick. Running simulated phishing campaigns allows teams to test employee awareness in real-world conditions and identify areas where further education is needed. It also helps normalize caution and keeps phishing front of mind.

Even the best defenses can’t guarantee that phishing attempts will always be caught. What matters most is how quickly employees and security teams respond. Every staff member should know exactly what to do if they suspect they have clicked a malicious link, downloaded an attachment or shared credentials: report it immediately to the IT or security team. From there, swift action is essential, as rapid detection and coordinated response are critical to minimizing damage. Security teams should:

• Isolate affected accounts or devices to prevent lateral movement.
• Reset compromised passwords and enforce multi-factor authentication.
• Scan systems for malware and remove malicious files.
• Review logs and network activity to assess the scope of the attack.

Phishing will remain one of the most persistent threats facing businesses, but having layered defenses at every level helps build resilience to these cyberthreats. Employees must stay alert to suspicious messages, supported by regular training and simulated phishing exercises. Meanwhile, technical solutions provide essential protection by blocking threats before they reach users and containing them if they slip through.

Long-term security requires vigilance. Cybercriminals continuously adapt their methods, so organizations must do the same by updating defenses, reviewing policies and monitoring networks in real-time. By combining awareness, advanced technologies and proactive response planning, firms can significantly reduce their exposure to phishing and protect their most valuable data assets.