Monday 05 February 2024 - Company news

TMHCC Top 10 Cyber Incidents 2023 report released

Tokio Marine HCC International announces Top 10 Cyber Incidents of 2023

  • TMHCC International’s fourth annual Top 10 Cyber Incidents report highlights the cyber-attack on Israel during the Israel-Hamas war as one of the most impactful cyber incidents of 2023.
  • Ransomware attacks made up four of the top 10, as the attack vector becomes an increasingly common weapon for cyber criminals.
  • Data breaches also had a major impact in 2023, with three separate incidents making the list

London, 5 February 2024

Tokio Marine HCC International (TMHCCI), a member of the Tokio Marine HCC group of companies, headquartered in Houston, Texas, has today released its Top 10 Cyber Incidents 2023 report.

Against a backdrop of rising geopolitical tension and growing cyber-criminal activity, the global insurer announces its Top 10 Cyber Incidents report. Based on an estimation of TMHCCI’s Cyber Security Insurance team, the list of the worst and most significant cyber incidents from 2023 has been compiled in terms of financial impact and reputational damage.

For the second year in a row, a nation-state attack is prominently featured on the list, with multiple significant cyber-attacks being launched by Hamas and its allies against Israel at the start of the conflict in the middle east. A large DDoS attack was detected against websites that provided critical information to civilians on rocket attacks, and criminal group AnonGhost also exploited a vulnerability in a mobile app that alerts Israeli civilians, most notably allowing them to intercept requests and send fake alerts.

In line with a growing presence of ransomware attacks, this attack vector featured heavily, making up four of the 10 spots on the list. Data breaches were the second most common type of attack, appearing three times.

The report also features the largest DDoS attack ever recorded – a failed attack on Google which peaked at 398 million requests per second.

Top 10 Cyber Incidents 2023 

TMHCCI’s top incidents list includes the following attacks:

  • Hamas’ kinetic cyber-attack against Israel
  • Supply chain attack against ION Derivatives
  • Data breaches caused by vulnerability in MoveIT software
  • LockBit ransomware attack against ICBC
  • “Scattered Spider” ransomware group attacks against Caesars and MGM Casinos
  • Marina Bay Sands data breach incident
  • Credit card data interception attack against Air Europa
  • LockBit ransomware attack against UK Royal Mail
  • LockBit ransomware attack against Boeing
  • Largest DDoS attack ever recorded against Google

Isaac Guasch, Cyber Security Leader at Tokio Marine HCC and one of the authors of the report, said: “The normalisation of cyber-attacks has meant that these stories do not make the headlines as much as they would in the past, but businesses must stay vigilant as criminal organisations such as LockBit continue to commercialise the industry, particularly in relation to ransomware. 2023 was a busy year for cyber criminals, and ransomware has proven to be one of the most profitable and effective attack vectors for the gangs to utilise, hence it’s prevalence in recent years. With the advent of new technologies to enable more effective attacks, this upwards trend is only going to accelerate.

“Nation-state cyber-attacks are now an important part of military aggression, working in tandem with real-world forces to neutralise defensive capabilities, as demonstrated in both Hamas’ attack on Israel and in Russia’s invasion of Ukraine. In the years to come, it is likely we will see these types of attacks continue to dominate the cyber security landscape.

“As is already frequently discussed, artificial intelligence (AI) is going from strength to strength. In an already highly dynamic industry, cybersecurity specialists are going to experience new waves of innovative attacks made possible through generative AI. However, by leveraging these new tools, businesses will also be able to bring about new innovative cybersecurity solutions, leading to a potential arms race between criminal gangs and those trying to stop them.”

The advent of generative AI

As in previous editions, the report also includes a ‘Bonus Track’, which for 2023 focuses on artificial intelligence and how the advent of AI solutions has led to an increase in sophisticated cyber-attacks. However, the authors reflect that these new tools will also form an essential part of cybersecurity, particularly as businesses look to make up for the lack of skilled cyber professionals globally.

The Microsoft Security Copilot is one solution mentioned within the report, which combines large language models, security-specific skills and global threat intelligence to enhance incident detection, response speed and overall security stance.

Although AI has already been present in cybersecurity tools as part of “Big Data” capabilities, generative AI has opened the door to a whole host of new possibilities for cyber criminals and professionals alike.

Access the full report for the complete data and comments.

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Tokio Marine HCC is a member of the Tokio Marine Group, a premier global company founded in 1879 with a market capitalization of $46 billion as of September 30, 2023. Headquartered in Houston, Texas, Tokio Marine HCC is a leading specialty insurance group with offices in the United States, Mexico, the United Kingdom and Continental Europe. Tokio Marine HCC’s major domestic insurance companies have financial strength ratings of ‘A+’ (Strong) from S&P Global Ratings, ‘A++’ (Superior) from A.M. Best, and ‘AA-’ (Very Strong) from Fitch Ratings; its major international insurance companies have financial strength ratings of ‘A+’ (Strong) from S&P Global Ratings. Tokio Marine HCC is the marketing name used to describe the affiliated companies under the common ownership of HCC Insurance Holdings, Inc., a Delaware-incorporated insurance holding company. For more information about Tokio Marine HCC, please visit

Max Steward, MHP Group
[email protected]
+44 (0)7586 050 758