sublimehighRule

Brand impersonation: Wells Fargo

Impersonation of Wells Fargo Bank.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1598.003 T1583.001

initial-access

Detection Query

type.inbound
and (
  sender.display_name =~ 'wellsfargo'
  or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                          'wellsfargo'
  ) <= 1
  or regex.icontains(strings.replace_confusables(sender.display_name),
                     'we(ll|ii)s?\s?farg(o|o͙)'
  )
  or strings.ilike(sender.email.domain.domain, '*wellsfargo*')
  or strings.ilike(subject.subject, '*wells fargo security*')
  or strings.ilike(body.plain.raw, '*wells fargo security team*')
  or strings.ilike(body.html.inner_text, '*wells fargo security team*')
)
and sender.email.domain.root_domain not in~ (
  'wellsfargo.com',
  'wellsfargoadvisors.com',
  'transunion.com',
  'wellsfargoemail.com',
  'wellsfargorewards.com',
  'comcast-spectacor.com',
  'investordelivery.com',
  'comcastspectacor.com',
  'wfadvisors.com',
  'wellsfargomerchantservicesllc.com'
)
and (
  sender.email.email not in $recipient_emails
  or regex.icontains(sender.email.email, "no.?reply")
)

// 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
  or sender.email.email in (
    "drive-shares-noreply@google.com",
    "drive-shares-dm-noreply@google.com"
  ) // Google Drive abuse has been observed
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

References

Raw Content

name: "Brand impersonation: Wells Fargo"
description: |
  Impersonation of Wells Fargo Bank.
references:
  - "https://www.americanbanker.com/news/wells-fargo-customers-targeted-with-phishing-attacks-using-calendar-invites"
  - "https://www.wellsfargo.com/biz/help/faqs/credit-card-rewards/"
type: "rule"
severity: "high"
source: |
  type.inbound
  and (
    sender.display_name =~ 'wellsfargo'
    or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                            'wellsfargo'
    ) <= 1
    or regex.icontains(strings.replace_confusables(sender.display_name),
                       'we(ll|ii)s?\s?farg(o|o͙)'
    )
    or strings.ilike(sender.email.domain.domain, '*wellsfargo*')
    or strings.ilike(subject.subject, '*wells fargo security*')
    or strings.ilike(body.plain.raw, '*wells fargo security team*')
    or strings.ilike(body.html.inner_text, '*wells fargo security team*')
  )
  and sender.email.domain.root_domain not in~ (
    'wellsfargo.com',
    'wellsfargoadvisors.com',
    'transunion.com',
    'wellsfargoemail.com',
    'wellsfargorewards.com',
    'comcast-spectacor.com',
    'investordelivery.com',
    'comcastspectacor.com',
    'wfadvisors.com',
    'wellsfargomerchantservicesllc.com'
  )
  and (
    sender.email.email not in $recipient_emails
    or regex.icontains(sender.email.email, "no.?reply")
  )
  
  // 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
    or sender.email.email in (
      "drive-shares-noreply@google.com",
      "drive-shares-dm-noreply@google.com"
    ) // Google Drive abuse has been observed
  )
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Impersonation: Brand"
  - "Lookalike domain"
  - "Social engineering"
detection_methods:
  - "Content analysis"
  - "Sender analysis"
id: "02d7301f-cc29-5031-9a1e-f013400805ba"