Microsoft confirms April Windows updates cause backup failures
Summary
Microsoft has confirmed that its April 2024 security updates are causing failures in third-party backup applications that utilize the psmounterex.sys driver. This issue impacts various backup solutions, preventing them from creating or restoring data. Microsoft is investigating the problem and working on a solution.
IFF Assessment
This update introduces a compatibility issue that directly impacts the ability of users to perform backups, a critical defense mechanism.
Defender Context
This incident highlights the importance of thorough testing before widespread deployment of software updates, especially those with security implications. Defenders should be aware of this issue and monitor for potential workarounds or patches from both Microsoft and affected backup vendors. It also underscores the dependency on third-party components within critical infrastructure like backup systems.