What is phishing?

Phishing remains the most pervasive and successful attack vector in cybersecurity. Despite decades of awareness campaigns and technical defenses, attackers continue to exploit human trust to steal credentials, deploy malware, and breach organizations of every size. At its core, phishing is a cyberattack where criminals use fraudulent emails, text messages, phone calls, or websites to trick individuals into revealing sensitive information or performing actions that compromise security.

Part of phishing’s dominance comes from its low cost and massive scalability. Unlike highly technical exploits, phishing requires minimal resources. Attackers often use ready-made phishing kits and vast botnets of compromised devices to send out millions of fraudulent messages daily. These infected machines act as unwitting distributors, allowing cybercriminals to operate anonymously and at scale for virtually no expense.

The numbers reflect phishing’s relentless growth. The Anti-Phishing Working Group recorded over 4.7 million phishing attacks worldwide in 2023, marking a 150 percent increase in two years. For five consecutive years, phishing has been the top-reported cybercrime to the FBI’s Internet Crime Complaint Center. Each year brings more targeted, convincing, and successful campaigns.

As organizations adopt hybrid work models and migrate more services to the cloud, phishing remains the preferred gateway for attackers to launch ransomware, business email compromise (BEC), and large-scale data breaches. Defending against it requires a multi-layered strategy that combines technical controls, user training, and real-time threat intelligence.

This article explores what phishing is, how it works, its various forms, and the serious consequences it can have for organizations.

Phishing explained

Phishing is a form of social engineering where attackers impersonate trusted individuals or organizations to deceive victims into taking harmful actions. These actions can include clicking malicious links, opening infected attachments, entering credentials into fake websites, or wiring money to fraudulent accounts.

The term “phishing” dates back to the 1990s when hackers targeted AOL users with fake emails requesting login credentials. Since then, phishing techniques have evolved from simple mass emails to highly targeted campaigns that exploit publicly available information about victims.

Today’s phishing attacks are often designed to bypass traditional security controls. They use carefully crafted messages that mimic corporate communications, urgent requests from executives, or alerts from service providers. Attackers rely on psychology—curiosity, fear, or a sense of urgency—to prompt users into making mistakes.

Phishing is not limited to email. It can arrive via text messages (smishing), phone calls (vishing), or even fake social media profiles (angler phishing). These multi-channel approaches make phishing harder to detect and stop.

Types of phishing

The phishing landscape is diverse, with several distinct tactics attackers use to achieve their goals.

Email phishing
This is the most widespread form of phishing. Attackers send mass emails posing as reputable companies, warning recipients of issues with their accounts or prompting them to verify information. Links in these emails often lead to convincing fake websites designed to harvest credentials.

Spear phishing
Unlike mass campaigns, spear phishing targets specific individuals or organizations. Attackers gather detailed information about their victims from public sources and craft personalized messages that are much harder to identify as fraudulent.

Whaling
This variant focuses on high-level executives and decision-makers. Whaling emails often use legal or financial pretexts to trick senior staff into authorizing wire transfers or revealing sensitive corporate data.

Smishing and vishing
Smishing uses text messages to deliver malicious links or instructions. Vishing relies on phone calls where attackers pose as IT support, vendors, or even government agencies. Recent campaigns have used AI-generated deepfake voices to impersonate executives convincingly.

Clone phishing
In this technique, attackers duplicate legitimate emails but replace attachments or links with malicious versions. Since the message appears to come from a known sender, victims are more likely to trust and act on it.

Angler phishing
This emerging tactic uses fake social media profiles to contact users and steal credentials or spread malware. As businesses increasingly use social platforms for customer service, angler phishing has become a growing threat.

How phishing works

Phishing campaigns typically follow a predictable pattern, though individual techniques vary.

Reconnaissance
Attackers begin by gathering information about their targets. For spear phishing, they may research employees on LinkedIn, analyze company hierarchies, or review recent press releases to craft believable pretexts.

Crafting the lure
The next step involves creating fraudulent messages or websites that mimic legitimate organizations. Attackers pay attention to logos, language, and formatting to avoid raising suspicion.

Delivery
Phishing messages are sent via email, SMS, social media, or phone calls. Attackers may also use compromised accounts to send phishing emails internally, increasing their credibility.

Engagement
The victim clicks a link, opens an attachment, or replies to the message. This action can lead to malware installation, credential theft, or financial fraud. In Business Email Compromise attacks, victims have been tricked into approving seven-figure wire transfers to fraudulent accounts.

Exploitation
Stolen credentials can be used for further intrusions, lateral movement, or as an entry point for ransomware deployment. Attackers often sell harvested credentials on dark web markets where they are later used in broader campaigns.

Impacts of phishing

Phishing attacks cause significant damage, often serving as the opening move in larger breaches.

Financial loss
The FBI reported that Business Email Compromise scams alone accounted for 2.7 billion dollars in losses in 2023. Costs include not just stolen funds but also remediation, legal fees, and penalties.

Data breaches
Credentials stolen through phishing often lead to unauthorized access to email systems, cloud services, and corporate networks. Attackers may exfiltrate sensitive data for extortion or resale.

Operational disruption
When phishing leads to ransomware deployment, organizations can suffer prolonged downtime. Hospitals have had to cancel appointments and divert patients because systems were locked by attackers.

Reputational damage
Customers and partners lose trust when an organization falls for a phishing attack. Public disclosure of a breach can lead to customer churn and long-term brand damage.

Regulatory exposure
Data protection laws such as GDPR and HIPAA impose strict requirements for reporting breaches. Failure to comply can result in fines and litigation.

Phishing’s true danger lies in its ability to bypass technical defenses by targeting human behavior. Organizations must prioritize user awareness and layered security to mitigate these risks.

Detection and prevention

Phishing may rely on deception rather than technical exploits, but that does not make it unstoppable. Organizations can significantly reduce risk with a multi-layered defense strategy that combines technology, processes, and people.

Advanced email security
Modern email security platforms use machine learning and heuristic analysis to block phishing emails before they reach users. These systems scan for malicious attachments, embedded links, and spoofed domains while also analyzing message tone and structure for social engineering cues.

DNS and web filtering
DNS protection adds another layer by blocking access to known phishing domains. If a user clicks a link in a fraudulent email, DNS filtering prevents their browser from reaching the malicious site.

Endpoint protection
If phishing manages to deliver a payload, endpoint protection systems can detect and quarantine suspicious processes. Behavioral analytics help identify unusual activity, such as unauthorized access attempts or credential harvesting.

Multifactor authentication (MFA)
MFA provides a critical safety net when credentials are compromised. Even if attackers obtain a user’s password, they cannot access accounts without a second authentication factor.

Threat intelligence and automation
Real-time threat intelligence helps security teams stay ahead of evolving phishing tactics. Automated security workflows can quickly disable compromised accounts or block malicious URLs across an organization.

User awareness and training
Humans remain the first line of defense. Regular phishing simulations and security awareness campaigns equip employees to spot and report suspicious emails. Over time, this fosters a security-conscious culture that is critical for preventing successful attacks.

AI’s role in phishing

Artificial intelligence has become a double-edged sword in the fight against phishing.

Offensive uses
Attackers are leveraging AI to craft highly convincing phishing emails. Large language models can generate grammatically perfect messages that mimic corporate communication styles, making them harder to detect. Deepfake audio and video are also emerging as tools for vishing and impersonation attacks.

Defensive uses
On the defensive side, AI-driven security platforms are analyzing millions of data points to identify subtle anomalies in email traffic and user behavior. Natural language processing detects tone shifts or unusual requests in messages, while behavioral analytics flags activities that deviate from normal patterns. AI-enabled orchestration allows security teams to respond in real time, stopping attacks before they escalate.

Organizations deploying AI-enhanced detection and response systems have seen a significant reduction in successful phishing attempts and related breaches, according to a 2024 Ponemon Institute study. The report highlights that organizations using AI extensively in prevention activities, like phishing detection, saw cost savings of approximately $2.2 million per breach

Responding to phishing

Even with robust defenses, some phishing attempts will inevitably slip through. A fast, coordinated response is critical to minimize damage.

The first step is containment. Compromised accounts should be immediately locked, and any malicious links or attachments should be blocked at the network level.

Next comes assessment. Security teams need to determine whether attackers gained access to sensitive data or systems and, if so, how far the breach has spread.

Eradication involves removing any malware or backdoors left behind. For organizations using endpoint detection and response tools, automated playbooks can accelerate this process.

Recovery includes restoring compromised accounts, enforcing password resets, and notifying affected users or regulators if required by law.

Finally, post-incident reviews should inform improvements to security posture, such as updating phishing filters, enhancing employee training, or refining incident response plans.

Notable case studies

Google and Facebook (2013–2015)
A Lithuanian scammer posed as a legitimate hardware vendor and tricked employees at Google and Facebook into wiring more than 100 million dollars to fraudulent accounts.

Sony Pictures (2014)
Phishing emails enabled attackers to infiltrate Sony’s network, leading to one of the most damaging breaches in corporate history. Sensitive emails and unreleased films were leaked online, causing massive reputational and financial harm.

Twitter (2020)
A spear phishing attack targeted Twitter employees with access to internal tools. The attackers hijacked high-profile accounts, including those of Elon Musk and Barack Obama, to promote a cryptocurrency scam.

Colonial Pipeline precursor attacks
Prior to the ransomware that halted US fuel supplies, attackers used phishing emails to steal VPN credentials, gaining initial access to the network.

Conclusion

Phishing is no longer a threat confined to inboxes. It is a versatile and evolving attack vector that serves as the launchpad for ransomware, data breaches, and financial fraud.

Defending against phishing requires a defense-in-depth strategy. Advanced email and DNS security, resilient backup systems, endpoint protection, threat intelligence, and user training all play critical roles. Multi-factor authentication adds an additional layer of protection when credentials are compromised.

No organization is immune, but those that invest in layered security and foster a culture of vigilance stand the best chance of avoiding the financial, operational, and reputational fallout of a successful attack. As phishing tactics grow more sophisticated, so too must the defenses designed to stop them.