Suspicious display name: Gmail sender with engaging language

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

Detects Gmail senders using display names with suspicious language patterns commonly associated with social engineering tactics, including urgency indicators, contact requests, and verification prompts.

Threat classification

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

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

Event coverage

Message attribute
body.current_thread
sender
sender.email
type

Rule body MQL

type.inbound
and 2 of (
  strings.icontains(sender.display_name, "kindly"),
  strings.icontains(sender.display_name, 'phone'),
  strings.icontains(sender.display_name, 'cell'),
  strings.icontains(sender.display_name, 'expedite'),
  strings.icontains(sender.display_name, 'urgent'),
  strings.icontains(sender.display_name, 'contact'),
  strings.icontains(sender.display_name, 'review'),
  strings.icontains(sender.display_name, 'confirm'),
  strings.icontains(sender.display_name, 'asap'),
  strings.icontains(sender.display_name, 'follow up'),
  strings.icontains(sender.display_name, 'nicely'),
  strings.icontains(sender.display_name, 'btc'),
  strings.icontains(sender.display_name, 'reply'),
  strings.icontains(sender.display_name, 'respond'),
  strings.icontains(sender.display_name, 'verify'),
  strings.icontains(sender.display_name, 'convenience'),
  strings.icontains(sender.display_name, 'response'),
  strings.icontains(sender.display_name, 'number'),
  strings.icontains(sender.display_name, 'mobile'),
  strings.icontains(sender.display_name, 'text'),
  strings.icontains(sender.display_name, 'request'),
  strings.icontains(sender.display_name, 'required'),
  strings.icontains(sender.display_name, 'important'),
  strings.icontains(sender.display_name, 'need'),
  strings.icontains(sender.display_name, 'quick'),
  strings.icontains(sender.display_name, 'sensitive'),
  strings.icontains(sender.display_name, 'reach'),
  strings.icontains(sender.display_name, 'action'),
  (
    strings.icontains(sender.display_name, 'monday')
    or strings.icontains(sender.display_name, 'tuesday')
    or strings.icontains(sender.display_name, 'wednesday')
    or strings.icontains(sender.display_name, 'thursday')
    or strings.icontains(sender.display_name, 'friday')
    or strings.icontains(sender.display_name, 'saturday')
    or strings.icontains(sender.display_name, 'sunday')
  ),
  (
    strings.icontains(sender.display_name, 'january')
    or strings.icontains(sender.display_name, 'february')
    or strings.icontains(sender.display_name, 'march')
    or strings.icontains(sender.display_name, 'april')
    or strings.icontains(sender.display_name, 'may')
    or strings.icontains(sender.display_name, 'june')
    or strings.icontains(sender.display_name, 'july')
    or strings.icontains(sender.display_name, 'august')
    or strings.icontains(sender.display_name, 'september')
    or strings.icontains(sender.display_name, 'october')
    or strings.icontains(sender.display_name, 'november')
    or strings.icontains(sender.display_name, 'december')
  )
)
and sender.email.domain.domain == 'gmail.com'
and length(attachments) == 0
and length(body.current_thread.links) == 0

Detection logic

Scope: inbound message.

inbound message
at least 2 of:
- sender.display_name contains 'kindly'
- sender.display_name contains 'phone'
- sender.display_name contains 'cell'
- sender.display_name contains 'expedite'
- sender.display_name contains 'urgent'
- sender.display_name contains 'contact'
- sender.display_name contains 'review'
- sender.display_name contains 'confirm'
- sender.display_name contains 'asap'
- sender.display_name contains 'follow up'
- sender.display_name contains 'nicely'
- sender.display_name contains 'btc'
- sender.display_name contains 'reply'
- sender.display_name contains 'respond'
- sender.display_name contains 'verify'
- sender.display_name contains 'convenience'
- sender.display_name contains 'response'
- sender.display_name contains 'number'
- sender.display_name contains 'mobile'
- sender.display_name contains 'text'
- sender.display_name contains 'request'
- sender.display_name contains 'required'
- sender.display_name contains 'important'
- sender.display_name contains 'need'
- sender.display_name contains 'quick'
- sender.display_name contains 'sensitive'
- sender.display_name contains 'reach'
- sender.display_name contains 'action'
- sender.display_name contains any of 7 patterns
  - monday
  - tuesday
  - wednesday
  - thursday
  - friday
  - saturday
  - sunday
- sender.display_name contains any of 12 patterns
  - january
  - february
  - march
  - april
  - may
  - june
  - july
  - august
  - september
  - october
  - november
  - december
sender.email.domain.domain is 'gmail.com'
length(attachments) is 0
length(body.current_thread.links) is 0

Inspects: body.current_thread.links, sender.display_name, sender.email.domain.domain, type.inbound. Sensors: strings.icontains.

Indicators matched (48)

Field	Match	Value
`strings.icontains`	substring	`kindly`
`strings.icontains`	substring	`phone`
`strings.icontains`	substring	`cell`
`strings.icontains`	substring	`expedite`
`strings.icontains`	substring	`urgent`
`strings.icontains`	substring	`contact`
`strings.icontains`	substring	`review`
`strings.icontains`	substring	`confirm`
`strings.icontains`	substring	`asap`
`strings.icontains`	substring	`follow up`
`strings.icontains`	substring	`nicely`
`strings.icontains`	substring	`btc`

36 more

`strings.icontains`	substring	`reply`
`strings.icontains`	substring	`respond`
`strings.icontains`	substring	`verify`
`strings.icontains`	substring	`convenience`
`strings.icontains`	substring	`response`
`strings.icontains`	substring	`number`
`strings.icontains`	substring	`mobile`
`strings.icontains`	substring	`text`
`strings.icontains`	substring	`request`
`strings.icontains`	substring	`required`
`strings.icontains`	substring	`important`
`strings.icontains`	substring	`need`
`strings.icontains`	substring	`quick`
`strings.icontains`	substring	`sensitive`
`strings.icontains`	substring	`reach`
`strings.icontains`	substring	`action`
`strings.icontains`	substring	`monday`
`strings.icontains`	substring	`tuesday`
`strings.icontains`	substring	`wednesday`
`strings.icontains`	substring	`thursday`
`strings.icontains`	substring	`friday`
`strings.icontains`	substring	`saturday`
`strings.icontains`	substring	`sunday`
`strings.icontains`	substring	`january`
`strings.icontains`	substring	`february`
`strings.icontains`	substring	`march`
`strings.icontains`	substring	`april`
`strings.icontains`	substring	`may`
`strings.icontains`	substring	`june`
`strings.icontains`	substring	`july`
`strings.icontains`	substring	`august`
`strings.icontains`	substring	`september`
`strings.icontains`	substring	`october`
`strings.icontains`	substring	`november`
`strings.icontains`	substring	`december`
`sender.email.domain.domain`	equals	`gmail.com`

`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)