Medium Severity
Spam: Link to blob.core.windows.net from new domain (<30d)
Description
This rule detects messages containing a link to blob.core.windows.net from a sender domain less than 30 days old. There is a single recipient present, but the recipient is a random email address, and not someone at the organization.
References
No references.
Sublime Security
Created May 21st, 2024 • Last updated Jul 16th, 2025
Feed Source
Sublime Core Feed
Source
type.inbound
and length(recipients.to) == 1
and any(recipients.to, .email.domain.root_domain not in $org_domains)
and network.whois(sender.email.domain).days_old < 30
and length(body.links) < 3
and any(body.links,
strings.ends_with(.href_url.domain.subdomain, "blob.core")
and .href_url.domain.root_domain == "windows.net"
)
and (
not profile.by_sender().solicited
or (
profile.by_sender().any_messages_malicious_or_spam
and not profile.by_sender().any_messages_benign
)
)
and not profile.by_sender().any_messages_benign
Playground
Test against your own EMLs or sample data.