Detection rules › Sublime MQL

Brand impersonation: Fastway

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

Impersonation of Fastway Couriers, a delivery services company in Ireland and South Africa.

Threat classification

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

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesImpersonation: Brand, Lookalike domain, Social engineering

Event coverage

Rule body MQL

type.inbound
and (
  strings.ilike(sender.display_name, '*fastway*')
  or strings.ilevenshtein(sender.display_name, 'fastway couriers') <= 1
)
and sender.email.domain.root_domain not in~ (
  'fastway.co.za',
  'fastway.com.au',
  'fastway.ie'
)

// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and not headers.auth_summary.dmarc.pass
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)

// and no false positives and not solicited
and (
  not profile.by_sender().any_messages_benign
  and not profile.by_sender().solicited
)

Detection logic

Scope: inbound message.

Impersonation of Fastway Couriers, a delivery services company in Ireland and South Africa.

  1. inbound message
  2. any of:
    • sender.display_name matches '*fastway*'
    • sender.display_name is similar to 'fastway couriers'
  3. sender.email.domain.root_domain not in ('fastway.co.za', 'fastway.com.au', 'fastway.ie')
  4. any of:
    • all of:
      • sender.email.domain.root_domain in $high_trust_sender_root_domains
      • not:
        • headers.auth_summary.dmarc.pass
    • sender.email.domain.root_domain not in $high_trust_sender_root_domains
  5. all of:
    • not:
      • profile.by_sender().any_messages_benign
    • not:
      • profile.by_sender().solicited

Inspects: headers.auth_summary.dmarc.pass, sender.display_name, sender.email.domain.root_domain, type.inbound. Sensors: profile.by_sender, strings.ilevenshtein, strings.ilike. Reference lists: $high_trust_sender_root_domains.

Indicators matched (5)

FieldMatchValue
strings.ilikesubstring*fastway*
strings.ilevenshteinfuzzyfastway couriers
sender.email.domain.root_domainmemberfastway.co.za
sender.email.domain.root_domainmemberfastway.com.au
sender.email.domain.root_domainmemberfastway.ie