Detection rules › Sublime MQL

Open redirect: amaterasu-for-website-5.com

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

Detects messages containing amaterasu-for-website-5.com redirect links that use the url parameter to redirect users to malicious sites. This has been observed in phishing campaigns.

Threat classification

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

CategoryValues
Attack typesCredential Phishing, Malware/Ransomware
Tactics and techniquesOpen redirect

Event coverage

Rule body MQL

type.inbound
and any(body.links,
        // Look for website-5 URLs
        .href_url.domain.domain == "api.amaterasu-for-website-5.com"
        and strings.icontains(.href_url.query_params, 'url=')
        // Make sure it's not redirecting back to website-5.com domains
        and not regex.icontains(.href_url.query_params,
                                'url=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*website-5\.com(?:\&|\/|$|%2f)'
        )
)
// Exclude legitimate website-5 domains as senders
and not sender.email.domain.root_domain == "website-5.com"
and not sender.email.domain.root_domain == "amaterasu-for-website-5.com"

// 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
)

Detection logic

Scope: inbound message.

Detects messages containing amaterasu-for-website-5.com redirect links that use the url parameter to redirect users to malicious sites. This has been observed in phishing campaigns.

  1. inbound message
  2. any of body.links where all hold:
    • .href_url.domain.domain is 'api.amaterasu-for-website-5.com'
    • .href_url.query_params contains 'url='
    • not:
      • .href_url.query_params matches 'url=(?:https?(?:%3a|:))?(?:%2f|\\/){2}[^&]*website-5\\.com(?:\\&|\\/|$|%2f)'
  3. not:
    • sender.email.domain.root_domain is 'website-5.com'
  4. not:
    • sender.email.domain.root_domain is 'amaterasu-for-website-5.com'
  5. 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

Inspects: body.links, body.links[].href_url.domain.domain, body.links[].href_url.query_params, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: regex.icontains, strings.icontains. Reference lists: $high_trust_sender_root_domains.

Indicators matched (5)

FieldMatchValue
body.links[].href_url.domain.domainequalsapi.amaterasu-for-website-5.com
strings.icontainssubstringurl=
regex.icontainsregexurl=(?:https?(?:%3a|:))?(?:%2f|\/){2}[^&]*website-5\.com(?:\&|\/|$|%2f)
sender.email.domain.root_domainequalswebsite-5.com
sender.email.domain.root_domainequalsamaterasu-for-website-5.com