Detection rules › Sublime MQL

Service abuse: Zoom with newly registered reply-to domain

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

Detects messages from legitimate Zoom infrastructure (no-reply@zoom.us) that contain a reply-to address with a domain registered within the last 45 days, indicating potential abuse of Zoom's service for malicious purposes.

Threat classification

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

CategoryValues
Attack typesSpam
Tactics and techniquesSocial engineering, Evasion

Event coverage

Rule body MQL

type.inbound
// Legitimate zoom sending infrastructure
and sender.email.email == "no-reply@zoom.us"
// newly registered reply-to domain
and network.whois(headers.reply_to[0].email.domain).days_old < 45

Detection logic

Scope: inbound message.

Detects messages from legitimate Zoom infrastructure (no-reply@zoom.us) that contain a reply-to address with a domain registered within the last 45 days, indicating potential abuse of Zoom's service for malicious purposes.

  1. inbound message
  2. sender.email.email is 'no-reply@zoom.us'
  3. network.whois(headers.reply_to[0].email.domain).days_old < 45

Inspects: headers.reply_to[0].email.domain, sender.email.email, type.inbound. Sensors: network.whois.

Indicators matched (1)

FieldMatchValue
sender.email.emailequalsno-reply@zoom.us