Detection rules › Sublime MQL

Link: Direct link to limewire hosted file

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

Message contains exactly one link to limewire.com domain with fewer than 10 total links in the body.

Threat classification

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

CategoryValues
Attack typesMalware/Ransomware
Tactics and techniquesFree file host

Event coverage

Rule body MQL

type.inbound
// there are few links
and length(body.links) < 10
// contains a link to limewire
and any(body.links, .href_url.domain.domain == "limewire.com")
// is the only link to limewire
and length(filter(body.links,
                  .href_url.domain.root_domain == "limewire.com"
                  and strings.istarts_with(.href_url.path, "/d/")
           )
) == 1
and not length(body.previous_threads) > 0
// 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
)
and not profile.by_sender_email().any_messages_benign

Detection logic

Scope: inbound message.

Message contains exactly one link to limewire.com domain with fewer than 10 total links in the body.

  1. inbound message
  2. length(body.links) < 10
  3. any of body.links where:
    • .href_url.domain.domain is 'limewire.com'
  4. length(filter(body.links, .href_url.domain.root_domain == 'limewire.com' and strings.istarts_with(.href_url.path, '/d/'))) is 1
  5. not:
    • length(body.previous_threads) > 0
  6. 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
  7. not:
    • profile.by_sender_email().any_messages_benign

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

Indicators matched (3)

FieldMatchValue
body.links[].href_url.domain.domainequalslimewire.com
body.links[].href_url.domain.root_domainequalslimewire.com
strings.istarts_withprefix/d/