Email security company Mimecast confirms hackers who breached its network downloaded source code. The SolarWinds hackers used the Sunburst backdoor to breach the company’s network earlier this year. The hackers accessed only a small, single-digit number of customers’ Microsoft 365 tenants after stealing a Microsoft-issued certificate used for securing Microsoft 365 cloud synchronization server tasks. The company believes the source code exfiltrated by the attackers is incomplete and insufficient to develop a working version of the service. No evidence was found of email or archive content being accessed.
Source: https://www.bleepingcomputer.com/news/security/mimecast-solarwinds-hackers-stole-some-of-our-source-code/