Most Dangerous 
Cyberattacks in 2025—
And the Expert Tactics 
to Stop Them

$13.82 trillion dollars. Let that sink in!

That’s the projected annual cost of global cybercrime by the year 2028. The actual cost could easily be much higher considering how sophisticated and evolving these threats have become.

But here's what's most alarming: we're not just looking at bigger numbers—we're witnessing a huge shift in how cyber warfare is conducted. Cybercriminals are no longer just sitting in basements - they are running a highly efficient business using automation, AI, and advanced social engineering to scale attacks and maximize impact. We have seen them using AI to write better phishing emails, launch ransomware-as-a-service, and slip past firewalls without even breaking a sweat.

Now, the question isn’t whether organizations need to understand these threats—it’s how urgently they’re prepared to act.

But before we get to that - what are the biggest threats to watch in 2025? What tactics are catching even the most well-defended companies off guard? And more importantly—what are the security experts doing to shut them down? Let's understand what we’re up against. 

16 Most Common Cyberattacks and How to Prevent Them?

1. Ransomware

Everyone is aware of the term ransomware; one would not need to be a security expert to know it.  

Ransomware encrypts files and demands payment, or ransom is paid in difficult-to-pay currencies, such as bitcoin or cryptocurrency. It can propagate across networks and cripple entire systems. Ransomware is one of the most prevalent and impactful cybersecurity threats in recent years, gaining significant attention due to its ability to cause widespread disruption, financial losses, and data breaches.

Also read - The Risks of Cybersecurity Technical Debt: Why Ignoring It Could Lead to Your Next Data Breach. 

How to defend against ransomware?

To safeguard against ransomware threats, organizations need multiple layers of protection, each reinforcing the other:

• Use immutable, air-gapped backups (e.g. AWS S3 Object Lock) to prevent attackers from tampering.
• Deploy EDR solutions like SentinelOne, or Microsoft Defender for Endpoint to detect suspicious behavior early.
• Ensure Privileged Access Management (PAM), restricting lateral movement by securing admin credentials.
• Isolate critical systems and use VLANs and firewalls to contain spread.
• Enforce MFA across all access points—especially VPN, RDP, cloud consoles, and email accounts. Opt for phishing-resistant MFA or certificate-based authentication for maximum protection.
• Engage Managed Detection and Response (MDR) providers or Managed Security Services Providers (MSSPs) that deliver.

2. Remote Code Execution (RCE) Attacks

Remote Code Execution (RCE) attacks occur when a cybercriminal exploits a vulnerable system—typically an unpatched application, misconfigured server, or outdated component—to execute arbitrary code from a remote location. These attacks often serve as the initial entry point in sophisticated campaigns, enabling threat actors to drop malware, establish backdoors, or move laterally across networks. Because RCE can be triggered without user interaction, it’s one of the most dangerous types of cyberattacks.

How to defend against RCE Attacks?

• Apply patches immediately for high-severity CVEs, especially those rated critical or exploited in the wild.
• Use virtual patching via Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) to block known exploit patterns when patching isn't immediately possible.
• Conduct continuous attack surface management (ASM) to discover and prioritize externally exposed systems.
• Use SIEMs with threat intelligence feeds to detect RCE indicators.
• Harden configurations by disabling remote code execution features and applying least-privilege access controls.

3. AI-Powered Polymorphic Malware Attacks

Polymorphic malware is a type of malicious software that continuously changes its code to evade detection by security tools. Attackers have taken cyberthreats up a notch —leveraging AI to rewrite, re-encrypt, or recompile malware payloads in real time, making traditional signature-based antivirus and static analysis tools nearly useless. These threats adapt to the target’s environment, identifying security tools and morphing their behavior to bypass them. Once inside, they can remain undetected for extended periods, quietly exfiltrating data or setting up for larger attacks like ransomware or credential theft.

It is found to use machine learning models to choose execution methods based on endpoint configuration, such as whether EDR is present, which ports are open, or which privileges the malware has upon arrival.

How to defend against defense evasion?

• Deploy AI-powered EDR/XDR solutions (like SentinelOne or Microsoft Defender for Endpoint) that use behavioral analysis, not just signatures, to detect malicious activity.
• Enable EDR tamper protection across all endpoints to block attackers from disabling or bypassing protection.
• Implement Memory-based scanning to detect suspicious in-memory execution patterns.
• Use Kernel-level driver allowlisting to block BYOVD (Bring Your Own Vulnerable Driver) techniques that polymorphic malware often abuse.
• Continuously monitor process behavior with automated SOAR playbooks to respond to anomalies in real time.

4. Drive-by compromise

Drive-by Compromise is a key initial access technique frequently used by both opportunistic malware campaigns and advanced attackers.

• A legitimate website may be compromised, allowing adversaries to inject malicious code
• Script files served to a legitimate website from a publicly writeable cloud storage bucket are modified by an adversary
• Malicious ads are paid for and served through legitimate ad providers (i.e., Malvertising), or via search engine optimization (SEO) poisoning.
• Built-in web application interfaces that allow user-controlled content are leveraged for the insertion of malicious scripts or iFrames.

It exploits browser vulnerabilities or weak endpoint defenses without any user interaction—no clicks, no downloads required.

How to defend against drive-by compromise?

• Remote Browser Isolation platforms open to all web content in sandboxed, cloud-based environments. Prevents any exploitation or script from execution locally.
• Use DNS-layer protection to block domains known to host exploit kits or malicious redirect chains.
• Integrate real-time threat intelligence feeds to update blocked domains/IPs.
• Enforce category-based filtering (e.g., blocking uncategorized or new domains).
• Disable vulnerable plugins using Group Policy or MDM solutions.
• Use Next-Gen Antivirus (NGAV) with exploit mitigation capabilities, such as: Heap spraying detection, Shellcode execution prevention, API hooking detection.
• Deploy a Secure Web Gateway (SWG) to inspect all outbound web traffic for: Malicious scripts, Drive-by redirect chains, Embedded iframes or hidden elements. SWGs can enforce SSL/TLS inspection to analyze HTTPS traffic where most drive-by payloads are now hidden.
• Monitor indicators of drive-by attacks on the SIEM or XDR platform.

5. Phishing Attacks

Phishing remains one of the most effective tools for cybercriminals due to its ability to exploit human trust. Attackers impersonate trusted entities via email, SMS, or social platforms to trick users into revealing sensitive information or downloading malware.  

Cybercriminals are also using AI-powered tools like large language models (LLMs) now, to craft highly personalized phishing emails— able to mimic tone, writing style, and context based on publicly available data (e.g., social media, LinkedIn, company press releases).

Also read - Anti-Phishing Services vs. Email Security: Key Differences and Why They Matter.

How to defend against phishing attacks

• Use Secure Email Gateways (SEGs) like Proofpoint or Mimecast to scan emails for malicious URLs, attachments, and header anomalies.
• DMARC, SPF, DKIM - Implement these email authentication protocols to verify the legitimacy of incoming and outgoing messages.
• Deploy sandboxing tools to scan links in real time before allowing user access.
• Use remote browser isolation (RBI) to isolate risky links in disposable containers.

6. Malware

Malware is a broad term that covers many different types of malicious software that can be installed on devices. Threat actors try to get malware installed on an endpoint—such as a laptop, desktop computer, or mobile phone. Malware includes viruses, Trojans, spyware, and worms. It typically infects systems via downloads, email, or USB devices.

How to defend against malware attacks

• Invest in an EDR tool for proactive malware defense that continuously monitors and analyzes endpoint activities.
• Go for 24/7 fully managed endpoint defense, covering advanced technology with human intelligence.
• Use Next-Gen Antivirus (NGAV) that relies on AI behavior modeling rather than signature-based detection.
• Lock down USB ports through device control solutions.

7. DDoS Attacks

A distributed denial of service (DDoS) uses multiple compromised devices to make an online service unavailable by temporarily interrupting, crashing, or corrupting the services of its hosting server. Simply put, DDoS attacks flood a network or server with requests, taking it offline. These attacks pose a growing threat to cloud services and large or small businesses alike. Attackers are also using AI to create adaptive DDoS campaigns that change vectors mid-attack, analyze target response, and evade traditional mitigation

How to defend against DDoS attacks

• Restrict traffic from abnormal geographies or apply rate limits per IP via web application firewalls.
• Use services like Azure DDoS Protection Standard to absorb and deflect high-volume traffic. Or distribute traffic to multiple data centers to absorb impact.
• Invest in advanced threat detection like Microsoft Sentinel.
• Conduct regular training and simulations for IT staff to ensure they are prepared.
• Develop a comprehensive incident response and recovery plan to minimize downtime, including IP blocking, casting, and black hole filtering.

8. Supply Chain Attacks

This type of cyberattack attempts to access or disrupt vital components of a company’s supply chain. Hackers infiltrate and compromise trusted suppliers or vendors to gain unauthorized control of sensitive data, hold assets ransom, or cause harm to an organization’s operations.  

Many cybersecurity experts believe the reason behind rising supply chain attacks to be:

• Increased reliance on open-source platforms, third-party vendors, and APIs.
• Poor security practices in the supply chain.

How to defend against supply chain attacks?

Preventing future supply chain attacks may be one of the toughest challenges a team will face. But all hope is not lost. Organizations can take below precautions to protect themselves against supply chain attacks, including:

• Using endpoint monitoring tools to spot and stop suspicious activity.
• Stay current with all system patches and updates.
• Implementing integrity controls to ensure users are only running tools from trusted sources.
• Requiring admins and other users to use multi-factor authentication.
• Demanding SBOMs from vendors to ensure software integrity.
• Requiring all third-party codes to be signed and validated before deployment.

In addition to the steps above, MSPs should have an effective incident response plan. Since supply chain attacks are relatively new, some are bound to infiltrate systems as we learn more and develop better protective techniques around it.

9. Insider Threats

83% of organizations reported at least one insider attack in the last year. These are security breaches caused by current or former employees, contractors, or partners with legitimate access to internal systems. Common outcomes include data theft, credential leaks, and privilege abuse, often driven by malicious intent or negligence. Insiders may steal IP, share passwords, disable security tools, or unknowingly open the door to external threats. AI is also being leveraged to automate data exfiltration without detection, schedule access during low-visibility hours, or mask file transfers using legitimate processes.

The top three drivers for insider threats include: complex IT environments (39%), adoption of new technologies (37%), and inadequate security measures (33%).

How to defend against insider threats?

• Insider threats rely on the negligence and actions of a company’s end users. Conduct cybersecurity awareness training.
• Implement tools and procedures to proactively monitor employees’ networks.
• Implement DLP systems to monitor data transfers.
• Provide temporary privileges only when necessary, using solutions like Azure PIM.
• Set up parameters and tools to monitor user behavior and establish strict cybersecurity protocols.

10. Business Email Compromise or BEC

BEC involves impersonating executives or partners to trick employees into transferring funds or data. Business emails can be compromised by cyberthreats in several ways, including:

• Phishing: Cybercriminals can use phishing emails to trick employees into divulging information, such as login credentials or financial information.
• Malware: Cybercriminals can use viruses or trojans to infect a user’s computer and gain access to their email accounts.
• Social engineering: These attacks trick employees into giving out sensitive information or granting access to their email accounts.
• Weak passwords: If employees use weak, reused, or easily guessable passwords, cybercriminals can use brute-force attacks to guess the password and gain access to the email account.

How to defend against business email compromise?

To protect against email threats, businesses can:  

• Use AI-based behavioral tools like Barracuda Sentinel to detect unusual sending patterns.
• Introduce mandatory out-of-band verification for large transfers.
• Ensure Role-based Access Control (RBAC) restricting financial authority to limited accounts after thorough auditing.
• Train employees in identifying and avoiding phishing emails, implement spam filters, etc.
• Insist employees use strong passwords and two-factor authentication.
• Keep software and cybersecurity systems up to date. 

11. Zero-Day Exploits

A zero-day exploit takes advantage of a security vulnerability unknown to the software vendor or developer. These vulnerabilities are particularly dangerous because no patch or update is available to fix the issue during the attack.  

Hackers can move quickly to exploit the flaw before it’s discovered and resolved. The exploits are often sold on the dark web and used in highly targeted attacks, making them a significant threat to individuals and businesses.

How to prevent zero-day exploits?

• Use advanced tools to identify unusual activities or anomalies as they happen.
• WAFs can provide temporary protection against unpatched vulnerabilities.
• Ensure all software and systems are up-to-date to close vulnerabilities.
• Stay informed about emerging threats and vulnerabilities. For that subscribe to feeds like MISP, Recorded Future, or FireEye to be in the known.

12. SQL Injection Attacks

SQL injection is a technique used by attackers to target web applications that rely on databases. It targets databases by inserting malicious queries through input fields on websites, compromising sensitive data, such as usernames, passwords, or credit card details. For instance: An attacker inputs malicious SQL in a website’s login form to trick the system into revealing or manipulating data in the backend database.

In severe cases, attackers can even manipulate or delete entire databases. SQL injection attacks are a common threat to poorly secured websites and can compromise millions of records in a single breach.

How to prevent SQL injection?

• Use input validation and parameterized queries to ensure user inputs are properly sanitized.  
• Use solutions like AWS WAF to detect and block injection attempts.
• Enforce parameterized statements in application code using ORM frameworks.
• Use tools like Oracle Audit Vault to track abnormal database queries.
• Regularly scan code for injection vulnerabilities using automated tools or manual reviews, or both.
• AI can automate the identification of vulnerable endpoints using advanced fuzzing techniques.

13. Man-in-the-Middle (MitM) Attacks

MitM attacks occur when a cybercriminal intercepts and potentially alters communications between two parties without their knowledge. Kind of like someone eavesdropping on a private conversation—sometimes rewriting or manipulating parts before reaching the other person.  

These attacks commonly target unsecured Wi-Fi networks, making public hotspots a prime risk. Attackers can steal sensitive information or compromise systems by intercepting data such as login credentials, financial information, or private messages.

How to prevent MitM (Man-in-the-Middle) attacks?

• Ensure websites interacted with, use HTTPS, which encrypts communication between the browser and the server, making it harder for attackers to intercept data.
• Use Virtual Private Network (VPN) to create a secure, encrypted tunnel for internet traffic, especially useful when using public Wi-Fi.
• Encrypt important information sent over the internet, ensuring it remains secure even if intercepted.
• Use Mutual TLS (mTLS) for certificate-based authentication between client and server to verify both sides of communication.

14. Cross-Site Scripting (XSS)

XSS attacks involve injecting malicious scripts into trusted web applications. These scripts execute in the browser of users who visit the infected page, enabling data theft, session hijacking, or malware delivery.

Different Types Include:

• Stored XSS: Malicious script is saved on the server (e.g., in comments).
• Reflected XSS: Script is reflected in the URL and executed immediately.
• DOM-based XSS: Executed via client-side JavaScript manipulation

How to stop Cross-Site Scripting (XSS)?

• Use frameworks that enforce output encoding, e.g., Microsoft AntiXSS library.
• Never trust user input; validate and sanitize using server-side logic.
• Ensure external scripts (CDNs) haven’t been tampered with by validating hashes.
• Use HttpOnly and Secure cookie flags to prevent cookie theft via XSS.
• Integrate DAST tools in CI/CD pipelines.

15. Credential Stuffing

Credential Stuffing uses stolen username-password combinations from one breach to try logging into other accounts. It's highly automated and fueled by massive credential leaks from the dark web. A famous credential stuffing incident was the Spotify attack where more than 100,000 credentials leaked from other services were used to log into thousands of Spotify accounts.

How to protect against Credential Stuffing?

• Enforce MFA using TOTP (e.g., Google Authenticator or certificate-based authentication.
• Integrate Credential Monitoring Services to detect when employee or user credentials appear in breaches. Initiate forced password resets for exposed accounts.
• Use bot detection platforms like CAPTCHAs.
• Limit the number of login attempts per IP/user within a set timeframe.
• Apply geo-based blocking or risk scoring to prevent access from high-risk countries.

16. Deepfake or Synthetic Identity Fraud

Both are on an upward trend, especially in financial services, identity verification, and executive impersonation scenarios. Attackers are using AI-generated media to bypass traditional verification methods and deceive both humans and systems.

• Deepfake fraud involves the use of AI-generated media—video, audio, or images—that impersonates a real person in real time or through pre-recorded content.
• Synthetic identity fraud involves creating entirely new, fake identities using AI-generated faces, fake documents, and stolen or fabricated PII (personally identifiable information).

These techniques are powered by Generative AI and other AI architectures capable of producing highly realistic but fake data.

How to protect against Deepfake or Synthetic Identity Fraud?

• Use Liveness Detection (Biometric), an AI-based facial or motion analysis.
• Analyze media for pixel-level or audio waveform anomalies typical of AI-generated content.
• Validate IDs using micro-text, holograms, metadata, and tamper detection via AI.
• Block access from emulators, spoofed devices, or high-risk configurations.
• Combine risk signals (identity, device, behavior) into dynamic fraud likelihood scores.

17. Social Engineering Attacks

Social engineering attacks manipulate human behavior to bypass security measures. Instead of exploiting technical vulnerabilities, attackers target people—tricking them into giving up credentials, clicking malicious links, or approving unauthorized actions. These attacks are often the first step in a larger breach, including ransomware, business email compromise, or insider misuse.

How to Defend Against Social Engineering Attacks?

• Use phishing-resistant multi-factor authentication (MFA) or smartcards to protect credentials.
• Employ email and message filtering tools with NLP and AI to flag impersonation, urgency scams, or suspicious links.
• Monitor unusual user behavior through UEBA tools (User and Entity Behavior Analytics).
• Implement just-in-time access controls to limit what a user can approve or access.
• Conduct simulated phishing campaigns and targeted awareness for high-risk roles.

18. AI-Powered CAPTCHA Solving Bots

Modern attackers are using machine learning models—particularly convolutional neural networks (CNNs)—to break through CAPTCHA and reCAPTCHA systems designed to differentiate humans from bots. These AI-powered bots are trained on thousands of CAPTCHA samples and can bypass image recognition, audio challenges, and text distortion mechanisms, allowing automated credential stuffing, fake account creation, or spam posting to proceed undeterred.

How to Defend Against AI CAPTCHA Bypass Attacks?

• Move beyond static CAPTCHAs by implementing behavioral analysis tools that track mouse movements, keystroke timing, and user patterns.
• Use risk-based authentication (RBA) that adapts challenges based on user behavior, IP reputation, and device fingerprinting.
• Integrate bot management platforms like Azure Bot Protection (via Azure Front Door), which use ML to distinguish humans from bots.
• Use honeypots or hidden form fields to detect bots bypassing interactive elements entirely.

With threats growing more advanced, persistent, and AI-powered, it's clear that protecting digital ecosystems now requires more than isolated tools or internal teams. Most organizations lack the in-house expertise, 24/7 visibility, and integrated platforms needed to detect, respond to, and recover from such sophisticated attacks.

This is where the role of a trusted Managed Security Services Provider (MSSP) like Cloud4C becomes absolutely indispensable.

Cloud4C: A Trusted Partner for End-to-End Cybersecurity Needs

As a globally trusted MSSP, Cloud4C offers end-to-end, AI-driven security solutions, covering AI-powered Managed Extended Detection and Response (AI MXDR), Security Operations Centre (SOC) services, advanced threat intelligence, and endpoint detection, all integrated with industry-leading platforms, applicable across multiple cloud/private environments. Leveraging frameworks such as MITRE ATT&CK and CIS Critical Security Controls, Cloud4C experts provide 24/7 monitoring, predictive analytics, automated incident response, and our self-healing operations that automatically isolate affected systems, roll back malicious changes, and restore critical services with minimal human intervention to protect against the rising threats we see above.

Our expertise extends to securing workloads across AWS, Azure, GCP, and Oracle. Cloud4C experts also secure hybrid, multi-cloud, private cloud, and on-premise environments—across all stages of cloud adoption, from migration to modernization. We also deploy a multi-layered defense strategy - covering AI-powered anti-phishing, advanced endpoint protection, vulnerability management, automated patching, real-time threat hunting, and data loss prevention.

With a proven track record of serving 60 of the Fortune 500 clients, our security experts ensure to maintain uncompromised security, regulatory compliance, and operational continuity in the face of the most sophisticated cyber risks.

To know more, contact us today! 

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