Detection rules › Sublime MQL

Link: Direct link to Zoom Docs from non-Zoom sender

Severity
medium
Type
rule
Source
github.com/sublime-security/sublime-rules

Message includes a single link to Zoom Docs, with no other links to zoom and originates from a sender outside the Zoom organization

Threat classification

Sublime's own taxonomy (not MITRE ATT&CK).

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesSocial engineering, Impersonation: Brand

Event coverage

Rule body MQL

type.inbound
// contains a link to zoom docs
and any(body.links, .href_url.domain.domain == "docs.zoom.us")
// is the only link to zoom
and length(filter(body.links, .href_url.domain.root_domain == "zoom.us")) == 1
// not from zoom.us
and not (
  sender.email.domain.root_domain == "zoom.us"
  and headers.auth_summary.dmarc.pass
)

Detection logic

Scope: inbound message.

Message includes a single link to Zoom Docs, with no other links to zoom and originates from a sender outside the Zoom organization

  1. inbound message
  2. any of body.links where:
    • .href_url.domain.domain is 'docs.zoom.us'
  3. length(filter(body.links, .href_url.domain.root_domain == 'zoom.us')) is 1
  4. not:
    • all of:
      • sender.email.domain.root_domain is 'zoom.us'
      • headers.auth_summary.dmarc.pass

Inspects: body.links, body.links[].href_url.domain.domain, body.links[].href_url.domain.root_domain, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound.

Indicators matched (3)

FieldMatchValue
body.links[].href_url.domain.domainequalsdocs.zoom.us
body.links[].href_url.domain.root_domainequalszoom.us
sender.email.domain.root_domainequalszoom.us