mimecast-web-componentsnpm
Advisory published Updated
mimecast-web-components is a confirmed malicious npm package (MAL-2026-3618) that executes malicious code on install (malicious version 2.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in mimecast-web-components (npm)
What this malware does
The OpenSSF Package Analysis project identified 'mimecast-web-components' @ 2.0.0 (npm) as malicious.
It is considered malicious because:
- The package executes one or more commands associated with malicious behavior.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for mimecast-web-components (version 2.0.0).
If you installed it — respond
Remove mimecast-web-components from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If mimecast-web-components was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Credits
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks mimecast-web-components-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.