Top 10 Biggest Cyber Attacks of 2024 & 25
Almost every month in 2024 came with its own shattering cybersecurity headline. We round up 10 of the biggest cyber attacks, data breaches and ransomware attacks from the year gone by. You’ll also find at the end of this blog a table of 25 other noteworthy attacks that you should know about.
2024 was one of the most significant years for the global IT and Security landscape. Attacks that ravaged critical service delivery, disrupted daily life and those whose impact continues to unravel well into 2025 grabbed eyeballs everywhere. If you so much as glance at our monthly compilations of biggest cyber attacks, data breaches and ransomware attacks, you’ll know what we’re talking about.
Here are some additional statistics to help you understand the urgency of enhancing your cybersecurity measures in 2025. The 2024 SonicWall Cyber Threat Report noted an approximate 107% surge in IoT malware attacks during the year. According to the “The State of Ransomware 2024” report by Sophos, ransomware impacted 59% of respondents. Phishing attacks skyrocketed by 4,151% since the public release of ChatGPT in late 2022, as reported by SlashNext in “The State of Phishing 2024.” Netscout recorded around 8 million DDoS attacks in the first half of 2024. The IBM/Ponemon Institute report stated that the average total cost of data breaches in 2024 was $4.88 million.
In light of the increasing sophistication of cyber attacks, such as the recent breaches detailed in the article, it’s crucial for organizations to conduct regular mobile app audits to identify and mitigate vulnerabilities in their applications.
We’ve compiled a list of the top 10 Biggest Cyber Attacks, Cybersecurity Events, Data Breaches and Ransomware Attacks for 2024.
In our opinion, these attacks made it to the top 10 list either thanks to their impact (financial or operational) or the massive scale at which they affected global services. Don’t forget to check out the table at the end of the other 25 big attacks you should know about!
Top 10 Biggest Cyber Attacks, Data Breaches and Ransomware Attacks of 2024
1. Change Healthcare Ransomware Attack
2. Snowflake Ransomware Attack
3. UK MoD Data Breach
4. Ascension Ransomware Attack
5. MediSecure Data Breach
6. Synnovis-NHS UK Ransomware Attack
7. CrowdStrike-Microsoft Outage
8. TfL Cyber Attack
9. Ivanti Mass Zero-Day Exploits
10. Salt Typhoon Attacks
The chair of the Senate Intelligence Committee, Senator Mark Warner, has called these attacks the “worst telecom hack in our nation’s history”. These intrusions granted the hackers access to sensitive data, such as call and text metadata, geolocation information, and, in certain cases, actual audio recordings of phone conversations. Notably, high-profile individuals, including political figures like Donald Trump and J.D. Vance, were among those affected.
The U.S. government has responded by implementing measures to bolster cybersecurity defences and mitigate the impact of these breaches. National Security Adviser Jake Sullivan confirmed that specific actions have been taken in response to the Salt Typhoon incidents. CISA has issued guidance to telecommunications providers, urging the adoption of robust security protocols, including encryption and continuous monitoring.
