C/side

cside is an American computer software company based in San Francisco, California. It is a business-focused organization that works in security and claims to have identified several large-scale browser-side supply chain attacks.[1]

History

cside was founded in 2024 by Simon Wijckmans [2] and launched publicly in May 2024.

Funding

In May 2024, cside announced it had raised $1.7 million in pre-seed funding.[3] In September 2024, the company raised a $6 million seed round led by cybersecurity and AI-focused investors.[4]

Research

cside has discovered and publicly disclosed details about large-scale security vulnerabilities, including large-scale browser-side supply chain attacks, including:

  • Polyfill Supply Chain Attack (June 2024): In February 2024, a Chinese company acquired the domain and GitHub account for Polyfill.io, a popular open-source library used by over 100,000 websites. Subsequently, the domain was used to inject malicious code into websites embedding scripts from cdn.polyfill.io, redirecting users to malicious sites. [5] [6][7] [8]
  • WordPress plug-in vulnerabilities (January 2025): In a coordinated campaign, attackers exploited vulnerabilities in outdated versions of WordPress and associated plugins to compromise thousands of websites, redirecting visitors to malicious domains or prompting them to download malware. [9] [10] [11]
  • WP3[.]XYZ Malware Attack (January 2025): A widespread malware campaign targeted over 5,000 WordPress websites, injecting malicious scripts from the domain wp3[.]xyz/td.js. The exact method of injection remains under investigation. [12][13] [14]
  • Malicious full-page hijack injection (March 2025): In February 2025,[15] a threat actor was observed targeting over 35,000 websites with a malicious full-page hijack injection; by March 2025, the campaign had expanded to impact an estimated 150,000 websites, using newly identified tactics and techniques. [16] [17] [18] [19]
  • North Korean schemes to get Western jobs (May 2025): In May 2025,[20] Wired Magazine worked with cside's CEO Simon Wijckmans to uncover the continued efforts of the North Korean government to place employees in Western companies.

References

  1. "cside Highlights the Growing Risks Around Client-side Web Application Security". TechTarget. 2025-03-31.
  2. "30 Under 30 - Europe - Technology (2025)". Forbes. 2025-04-19.
  3. "cside Emerges from Stealth with $1.7 Million in Funding". GlobeNewswire. 2024-05-16.
  4. "cside Raises $6M in Seed Funding". SecurityWeek. 2024-09-17.
  5. "More than 490k websites targeted in web supply chain attack". cside blog. 2024-06-24.
  6. "Formerly legitimate Polyfill.io domain abused to serve malicious code". CSO Online. 2024-06-24.
  7. "If you're using Polyfill.io code on your site – like 100,000+ are – remove it immediately". The Register. 2024-06-24.
  8. "Polyfill Supply Chain Attack Hits Over 100k Websites". Security Week. 2024-06-24.
  9. "10,000 WordPress Websites Found Delivering MacOS and Windows Malware". cside blog. 2025-01-27.
  10. "Hackers are hijacking WordPress sites to push Windows and Mac malware". TechCrunch. 2025-01-29.
  11. "Hackers Use 10,000 WordPress Sites To Deliver Malware To macOS and Microsoft Systems". Cyber Security News. 2025-01-30.
  12. "Over 5,000 WordPress sites caught in WP3[.]XYZ malware attack". cside blog. 2025-01-13.
  13. "WP3.XYZ malware attacks add rogue admins to 5,000+ WordPress sites". Bleeping Computer. 2025-01-14.
  14. "Thousands of WordPress Websites Hit in New Malware Attack, Here's What We Know". TechRadar. 2025-01-15.
  15. "Over 35,000 Websites Targeted in Full-Page Hijack Linking to a Chinese-Language Gambling Scam". cside blog. 2025-02-20.
  16. "Over 150K websites hit by full-page hijack linking to Chinese gambling sites". cside blog. 2025-03-26.
  17. "Thousands of websites have now been hijacked by this devious, and growing, malicious scheme". MSN.com. 2025-03-28.
  18. "Threat Actors Hacked 150,000 Sites to Link Chinese Gambling Sites". Cyber Security News. 2025-03-28.
  19. "150,000 Sites Compromised by JavaScript Injection Promoting Chinese Gambling Platforms". The HackerNews. 2025-03-27.
  20. "North Korea Stole Your Job". Wired. 2025-05-01.