Detection rules › Sublime MQL

Service abuse: Behance document sharing with suspicious language

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

Detects messages containing document sharing language with a single Behance gallery link, potentially indicating abuse of the legitimate Adobe Behance platform for malicious purposes.

Threat classification

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

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesFree file host, Social engineering

Event coverage

Rule body MQL

type.inbound
and length(body.current_thread.text) < 10000
and strings.ilike(body.current_thread.text,
                  "*proposal*",
                  "*specified link*",
                  "*secure*"
)
and length(filter(body.current_thread.links,
                  .href_url.domain.root_domain == 'behance.net'
                  and strings.icontains(.href_url.path, '/gallery/')
                  and .display_url.domain.root_domain == 'behance.net'
                  and strings.icontains(.display_url.path, '/gallery/')
           )
) == 1
and not (
  sender.email.domain.root_domain in $high_trust_sender_root_domains
  and coalesce(headers.auth_summary.dmarc.pass, false)
)

Detection logic

Scope: inbound message.

Detects messages containing document sharing language with a single Behance gallery link, potentially indicating abuse of the legitimate Adobe Behance platform for malicious purposes.

  1. inbound message
  2. length(body.current_thread.text) < 10000
  3. body.current_thread.text matches any of 3 patterns
    • *proposal*
    • *specified link*
    • *secure*
  4. length(filter(body.current_thread.links, .href_url.domain.root_domain == 'behance.net' and strings.icontains(.href_url.path, '/gallery/') and .display_url.domain.root_domain == 'behance.net' and strings.icontains(.display_url.path, '/gallery/'))) is 1
  5. not:
    • all of:
      • sender.email.domain.root_domain in $high_trust_sender_root_domains
      • coalesce(headers.auth_summary.dmarc.pass)

Inspects: body.current_thread.links, body.current_thread.links[].display_url.domain.root_domain, body.current_thread.links[].display_url.path, body.current_thread.links[].href_url.domain.root_domain, body.current_thread.links[].href_url.path, body.current_thread.text, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: strings.icontains, strings.ilike. Reference lists: $high_trust_sender_root_domains.

Indicators matched (6)

FieldMatchValue
strings.ilikesubstring*proposal*
strings.ilikesubstring*specified link*
strings.ilikesubstring*secure*
body.current_thread.links[].href_url.domain.root_domainequalsbehance.net
strings.icontainssubstring/gallery/
body.current_thread.links[].display_url.domain.root_domainequalsbehance.net