Ransomware Attacks Soar 146% with Data Exfiltration Tactics on the Rise

Zscaler's annual ThreatLabz 2025 Ransomware Report reveals a 146% YoY increase in ransomware attacks blocked by its cloud platform. Ransomware groups stole 238 TB of data, a 92% rise compared to the previous year. Manufacturing, Technology, and Healthcare were top targets, with Oil & Gas seeing a 935% rise in attacks. The US accounted for 50% of all ransomware attacks, with RansomHub being the most active ransomware group. Zscaler advocates for Zero Trust strategies to combat evolving threats.

Zscaler's annual ThreatLabz 2025 Ransomware Report reveals a significant surge in ransomware attacks, with the company's cloud platform blocking a staggering 146% more attacks year-over-year. This escalation underscores the growing threat landscape and the evolving tactics employed by cybercriminals.

Key findings from the report include a 92% increase in data exfiltration volumes, with ransomware groups stealing 238 TB of data in the past year. This surge reflects a strategic shift towards extortion tactics, where attackers prioritize data theft over encryption. The report also highlights the most targeted industries, with Manufacturing, Technology, and Healthcare sectors experiencing the highest number of attacks. Notably, the Oil & Gas sector saw a 935% rise in attacks, indicating significant vulnerabilities in critical infrastructure security measures.

The United States accounted for 50% of all ransomware attacks, with RansomHub being the most active ransomware group. This concentration of attacks in the U.S. raises concerns about the effectiveness of Zscaler's security measures in its primary market.

To combat these evolving threats, Zscaler advocates for a Zero Trust security strategy. This approach aims to minimize vulnerabilities and enhance protection against ransomware threats. The company emphasizes the importance of preventing lateral movement and stopping data exfiltration to mitigate the impact of extortion events.

The report provides actionable recommendations for organizations to strengthen their defenses against ransomware attacks. It underscores the critical importance of adopting a comprehensive Zero Trust Everywhere strategy to stay ahead of the rapidly evolving threat landscape.

References:

[1] https://www.quiverquant.com/news/Zscaler+Report+Reveals+146%25+Surge+in+Ransomware+Attacks+and+Growing+Threat+Landscape+in+2025