sublimehighRule

Brand impersonation: Coinbase

Impersonation of the cryptocurrency exchange Coinbase to harvest Coinbase credentials or related information.

MITRE ATT&CK

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

initial-access

Detection Query

type.inbound
and (
  strings.ilike(strings.replace_confusables(sender.display_name), '*coinbase*')
  or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                          'coinbase'
  ) <= 1
  or strings.ilike(sender.email.domain.domain, '*coinbase*')
)
and not (
  sender.email.domain.root_domain in (
    'coinbase.com',
    'q4inc.com',
    'sendsafely.com' // used by Coinbase for verification codes
  )
  and headers.auth_summary.dmarc.pass
)
and (
  // if this comes from a free email provider,
  // flag if org has never sent an email to sender's email before
  (
    sender.email.domain.root_domain in $free_email_providers
    and sender.email.email not in $recipient_emails
  )
  // if this comes from a custom domain,
  // flag if org has never sent an email to sender's domain before
  or (
    sender.email.domain.root_domain not in $free_email_providers
    and sender.email.domain.domain not in $recipient_domains
  )
)

// 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
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

References

https://blog.coinbase.com/phishing-attacks-and-how-to-not-fall-victim-42b489d77199

Tags

Cryptocurrency

Raw Content

name: "Brand impersonation: Coinbase"
description: |
  Impersonation of the cryptocurrency exchange Coinbase to harvest Coinbase credentials 
  or related information.
references:
  - "https://blog.coinbase.com/phishing-attacks-and-how-to-not-fall-victim-42b489d77199"
type: "rule"
severity: "high"
source: |
  type.inbound
  and (
    strings.ilike(strings.replace_confusables(sender.display_name), '*coinbase*')
    or strings.ilevenshtein(strings.replace_confusables(sender.display_name),
                            'coinbase'
    ) <= 1
    or strings.ilike(sender.email.domain.domain, '*coinbase*')
  )
  and not (
    sender.email.domain.root_domain in (
      'coinbase.com',
      'q4inc.com',
      'sendsafely.com' // used by Coinbase for verification codes
    )
    and headers.auth_summary.dmarc.pass
  )
  and (
    // if this comes from a free email provider,
    // flag if org has never sent an email to sender's email before
    (
      sender.email.domain.root_domain in $free_email_providers
      and sender.email.email not in $recipient_emails
    )
    // if this comes from a custom domain,
    // flag if org has never sent an email to sender's domain before
    or (
      sender.email.domain.root_domain not in $free_email_providers
      and sender.email.domain.domain not in $recipient_domains
    )
  )
  
  // 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
  )
tags:
  - "Cryptocurrency"
attack_types:
  - "Credential Phishing"
tactics_and_techniques:
  - "Impersonation: Brand"
  - "Lookalike domain"
  - "Social engineering"
detection_methods:
  - "Header analysis"
  - "Sender analysis"
id: "3dca757a-fb21-53c0-ac17-b0f110e8db60"