Brand Impersonation: Procore

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

Detects messages containing Procore branding language that do not originate from legitimate Procore domains. This has been observed in phishing campaigns.

Threat classification

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

Category	Values
Attack types	BEC/Fraud, Credential Phishing
Tactics and techniques	Impersonation: Brand, Social engineering

Event coverage

Message attribute
attachments (collection)
body.current_thread
headers (collection)
headers.auth_summary
sender
sender.email
subject
type

Rule body MQL

type.inbound
and (
  strings.ilike(body.current_thread.text, "*powered by procore*")
  or 2 of (
    strings.icontains(body.current_thread.text, 'Procore'),
    strings.icontains(body.current_thread.text, '6309 Carpinteria Ave'),
    strings.icontains(body.current_thread.text, 'Carpinteria, CA 93013')
  )
  or (
    strings.iends_with(sender.display_name, 'via Procore')
    and any(body.current_thread.links,
            .href_url.domain.root_domain in $free_subdomain_hosts
    )
  )
)
and not (
  sender.email.domain.root_domain in ("procore.com", "procoretech.com")
  and coalesce(headers.auth_summary.dmarc.pass, false)
)

// negating legit replies/forwards
and not (
  (
    strings.istarts_with(subject.subject, "RE:")
    or strings.istarts_with(subject.subject, "FW:")
    or strings.istarts_with(subject.subject, "FWD:")
    or regex.imatch(subject.subject,
                    '(\[[^\]]+\]\s?){0,3}(re|fwd?|automat.*)\s?:.*'
    )
    or strings.istarts_with(subject.subject, "Réponse automatique")
  )
  and (length(headers.references) > 0 and headers.in_reply_to is not null)
)
// negate bounce backs
and not (
  strings.like(sender.email.local_part,
               "*postmaster*",
               "*mailer-daemon*",
               "*administrator*"
  )
  and any(attachments,
          .content_type in (
            "message/rfc822",
            "message/delivery-status",
            "text/calendar"
          )
  )
)

Detection logic

Scope: inbound message.

Detects messages containing Procore branding language that do not originate from legitimate Procore domains. This has been observed in phishing campaigns.

inbound message
any of:
- body.current_thread.text matches '*powered by procore*'
- at least 2 of:
  - body.current_thread.text contains 'Procore'
  - body.current_thread.text contains '6309 Carpinteria Ave'
  - body.current_thread.text contains 'Carpinteria, CA 93013'
- all of:
  - sender.display_name ends with 'via Procore'
  - any of body.current_thread.links where:
    
    .href_url.domain.root_domain in $free_subdomain_hosts
not:
- all of:
  - sender.email.domain.root_domain in ('procore.com', 'procoretech.com')
  - coalesce(headers.auth_summary.dmarc.pass)
not:
- all of:
  - any of:
    
    subject.subject starts with 'RE:'
    subject.subject starts with 'FW:'
    subject.subject starts with 'FWD:'
    subject.subject matches '(\\[[^\\]]+\\]\\s?){0,3}(re|fwd?|automat.*)\\s?:.*'
    subject.subject starts with 'Réponse automatique'
  - all of:
    
    length(headers.references) > 0
    headers.in_reply_to is set
not:
- all of:
  - sender.email.local_part matches any of 3 patterns
    
    *postmaster*
    *mailer-daemon*
    *administrator*
  - any of attachments where:
    
    .content_type in ('message/rfc822', 'message/delivery-status', 'text/calendar')

Inspects: attachments[].content_type, body.current_thread.links, body.current_thread.links[].href_url.domain.root_domain, body.current_thread.text, headers.auth_summary.dmarc.pass, headers.in_reply_to, headers.references, sender.display_name, sender.email.domain.root_domain, sender.email.local_part, subject.subject, type.inbound. Sensors: regex.imatch, strings.icontains, strings.iends_with, strings.ilike, strings.istarts_with, strings.like. Reference lists: $free_subdomain_hosts.

Indicators matched (18)

Field	Match	Value
`strings.ilike`	substring	`powered by procore`
`strings.icontains`	substring	`Procore`
`strings.icontains`	substring	`6309 Carpinteria Ave`
`strings.icontains`	substring	`Carpinteria, CA 93013`
`strings.iends_with`	suffix	`via Procore`
`sender.email.domain.root_domain`	member	`procore.com`
`sender.email.domain.root_domain`	member	`procoretech.com`
`strings.istarts_with`	prefix	`RE:`
`strings.istarts_with`	prefix	`FW:`
`strings.istarts_with`	prefix	`FWD:`
`regex.imatch`	regex	`(\[[^\]]+\]\s?){0,3}(re\|fwd?\|automat.)\s?:.`
`strings.istarts_with`	prefix	`Réponse automatique`

6 more

`strings.like`	substring	`postmaster`
`strings.like`	substring	`mailer-daemon`
`strings.like`	substring	`administrator`
`attachments[].content_type`	member	`message/rfc822`
`attachments[].content_type`	member	`message/delivery-status`
`attachments[].content_type`	member	`text/calendar`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)