Low Severity
Brand impersonation: American Express (AMEX)
Description
Impersonation of the credit card provider American Express.
Sublime Security
Created Aug 17th, 2023 • Last updated Jul 10th, 2025
Feed Source
Sublime Core Feed
Source
type.inbound
and (
regex.icontains(sender.display_name, 'american ?express')
or strings.ilike(sender.display_name, "*amer?can expres*")
or strings.ilevenshtein(sender.display_name, 'american express') <= 2
or strings.ilike(sender.email.domain.domain, '*americanexpress*')
)
and sender.email.domain.root_domain not in (
'aexp.com',
'americanexpress.ae',
'americanexpress.com',
'americanexpress.co.uk',
'americanexpress.com.bh',
'aexpfeedback.com',
'amexnetwork.com',
'accountonline.com',
'transunion.com',
'amexgiftcard.com',
'amexgbt.com',
'herrickstravelamex.com',
'citi.com',
'secure.com',
'nectar.com',
'accentinfomedia.com',
'egencia.com'
)
and sender.email.domain.domain not in ('accountprotection.microsoft.com', 'amex.membershipmail.net')
and not profile.by_sender().solicited
// 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
)
Playground
Test against your own EMLs or sample data.