08 June 2026
1. What is being reported?
Hackers have used a worm called Miasma to infect multiple Microsoft GitHub repositories. These repositories are places where software code is stored and shared. By compromising them, attackers can insert harmful code that might be unknowingly used by developers and businesses.
2. What this means in plain English
If your organisation uses software or tools that come from these affected repositories, there is a risk that malicious code could be included in your systems. This could allow attackers to take control of your computers or steal information.
3. Could this affect a small business?
Small businesses that use Microsoft software or tools developed through GitHub could be affected, especially if their software updates or installs include code from these compromised repositories. Organisations not using such software or relying on trusted IT providers who manage updates are less likely to be impacted.
4. What to do now
- Ask your IT provider if any software your organisation uses comes from Microsoft GitHub repositories and whether they have checked for this issue.
- Ensure all software and systems are updated promptly with official patches or fixes from trusted sources.
- Avoid downloading or installing software from unofficial or unknown sources.
- Monitor your systems for unusual activity and report any concerns to your IT support.
5. Ask your IT provider
Can you confirm whether any software we use is affected by the recent Microsoft GitHub Miasma Worm supply chain attack, and what steps you have taken to protect us?
6. Bottom line
Stay in touch with your IT support to ensure your software is safe and up to date following this supply chain attack.
Information based on reputable security reporting and CISA KEV.