Detection rules › Sublime MQL

Service abuse: HungerRush domain with SendGrid tracking targeting ProtonMail

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

Detects inbound messages from hungerrush.com domain that contain SendGrid tracking pixels and reference redacted ProtonMail addresses, indicating potential abuse of legitimate services for suspicious targeting.

Threat classification

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

CategoryValues
Attack typesBEC/Fraud
Tactics and techniquesEvasion

Event coverage

Rule body MQL

type.inbound
and sender.email.domain.root_domain == "hungerrush.com"
// html contains sendgrid open tracking pixel
and strings.icontains(body.html.raw, 'sendgrid.net/wf/open')
// body contains "redacted" proton email address
and regex.icontains(body.current_thread.text, '(?:\*\*|protonmail\.com)')

Detection logic

Scope: inbound message.

Detects inbound messages from hungerrush.com domain that contain SendGrid tracking pixels and reference redacted ProtonMail addresses, indicating potential abuse of legitimate services for suspicious targeting.

  1. inbound message
  2. sender.email.domain.root_domain is 'hungerrush.com'
  3. body.html.raw contains 'sendgrid.net/wf/open'
  4. body.current_thread.text matches '(?:\\*\\*|protonmail\\.com)'

Inspects: body.current_thread.text, body.html.raw, sender.email.domain.root_domain, type.inbound. Sensors: regex.icontains, strings.icontains.

Indicators matched (3)

FieldMatchValue
sender.email.domain.root_domainequalshungerrush.com
strings.icontainssubstringsendgrid.net/wf/open
regex.icontainsregex(?:\*\*|protonmail\.com)