Detection rules › Sublime MQL

Link: .onion From Unsolicited Sender

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

Detects messages containing .onion (Tor network) links from unsolicited senders that either lack proper DMARC authentication or are not from trusted domains.

Threat classification

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

CategoryValues
Attack typesMalware/Ransomware, Credential Phishing
Tactics and techniquesEvasion, Social engineering

Event coverage

Rule body MQL

type.inbound
and any(body.links, .href_url.domain.tld == "onion")
and not profile.by_sender_email().solicited
// and the sender is not from high trust sender root domains
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 .onion (Tor network) links from unsolicited senders that either lack proper DMARC authentication or are not from trusted domains.

  1. inbound message
  2. any of body.links where:
    • .href_url.domain.tld is 'onion'
  3. not:
    • profile.by_sender_email().solicited
  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

Inspects: body.links, body.links[].href_url.domain.tld, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: profile.by_sender_email. Reference lists: $high_trust_sender_root_domains.

Indicators matched (1)

FieldMatchValue
body.links[].href_url.domain.tldequalsonion