Brand impersonation: Amazon with suspicious attachment

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

Impersonation of Amazon. These are most commonly fake shipping notifications. Amazon is the #2 most-impersonated brand (as of Q2 2020)

Threat classification

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

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

Event coverage

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

Rule body MQL

type.inbound
and (
  strings.ilike(sender.display_name, "amazon*")
  or any(attachments, strings.icontains(.file_name, "amazon"))
  or any(attachments,
         (.file_type in $file_types_images or .file_type == "pdf")
         and any(file.explode(.), strings.icontains(.scan.ocr.raw, "amazon"))
  )
)
and any(attachments,
        (.file_type in $file_types_images or .file_type == "pdf")
        and any(ml.logo_detect(.).brands,
                .name == "Amazon" and .confidence in~ ("medium", "high")
        )
        and (
          any(file.explode(.),
              any(ml.nlu_classifier(.scan.ocr.raw).intents,
                  .name != "benign" and .confidence == "high"
              )
          )
          or any(ml.nlu_classifier(body.current_thread.text).intents,
                 .name != "benign" and .confidence == "high"
          )
        )
)
and (
  not profile.by_sender().solicited
  or (
    profile.by_sender().any_messages_malicious_or_spam
    and not profile.by_sender().any_messages_benign
  )
)
and sender.email.domain.root_domain not in~ (
  'a2z.com',
  'amazon.com',
  'amazon.com.au',
  'amazon.co.uk',
  'amazon.de',
  'amazon.es',
  'amazon.fr',
  'amazon.it',
  'amazon.in',
  'amazon.lu',
  'amazon.com.au',
  'amazonsellerservices.com',
  'amazon.ae',
  'amazon.sa',
  'amazon.cn',
  'amazon.ca',
  'amazon.com.mx',
  'amazon.com.br',
  'amazon.ph',
  'amazon.sg',
  'amazon.com.tr',
  'amazonpay.in',
  'amazonpay.com',
  'synchronybank.com',
  'aws.com'
)

Detection logic

Scope: inbound message.

Impersonation of Amazon. These are most commonly fake shipping notifications. Amazon is the #2 most-impersonated brand (as of Q2 2020)

inbound message
any of:
- sender.display_name matches 'amazon*'
- any of attachments where:
  - .file_name contains 'amazon'
- any of attachments where all hold:
  - any of:
    
    .file_type in $file_types_images
    .file_type is 'pdf'
  - any of file.explode(.) where:
    
    .scan.ocr.raw contains 'amazon'
any of attachments where all hold:
- any of:
  - .file_type in $file_types_images
  - .file_type is 'pdf'
- any of ml.logo_detect(.).brands where all hold:
  - .name is 'Amazon'
  - .confidence in ('medium', 'high')
- any of:
  - any of file.explode(.) where:
    
    any of ml.nlu_classifier(.scan.ocr.raw).intents where all hold:
    
    .name is not 'benign'
    .confidence is 'high'
  - any of ml.nlu_classifier(body.current_thread.text).intents where all hold:
    
    .name is not 'benign'
    .confidence is 'high'
any of:
- not:
  - profile.by_sender().solicited
- all of:
  - profile.by_sender().any_messages_malicious_or_spam
  - not:
    
    profile.by_sender().any_messages_benign
sender.email.domain.root_domain not in ('a2z.com', 'amazon.com', 'amazon.com.au', 'amazon.co.uk', 'amazon.de', 'amazon.es', 'amazon.fr', 'amazon.it', 'amazon.in', 'amazon.lu', 'amazon.com.au', 'amazonsellerservices.com', 'amazon.ae', 'amazon.sa', 'amazon.cn', 'amazon.ca', 'amazon.com.mx', 'amazon.com.br', 'amazon.ph', 'amazon.sg', 'amazon.com.tr', 'amazonpay.in', 'amazonpay.com', 'synchronybank.com', 'aws.com')

Inspects: attachments[].file_name, attachments[].file_type, body.current_thread.text, sender.display_name, sender.email.domain.root_domain, type.inbound. Sensors: file.explode, ml.logo_detect, ml.nlu_classifier, profile.by_sender, strings.icontains, strings.ilike. Reference lists: $file_types_images.

Indicators matched (32)

Field	Match	Value
`strings.ilike`	substring	`amazon*`
`strings.icontains`	substring	`amazon`
`attachments[].file_type`	equals	`pdf`
`ml.logo_detect(attachments[]).brands[].name`	equals	`Amazon`
`ml.logo_detect(attachments[]).brands[].confidence`	member	`medium`
`ml.logo_detect(attachments[]).brands[].confidence`	member	`high`
`ml.nlu_classifier(file.explode(attachments[])[].scan.ocr.raw).intents[].confidence`	equals	`high`
`ml.nlu_classifier(body.current_thread.text).intents[].confidence`	equals	`high`
`sender.email.domain.root_domain`	member	`a2z.com`
`sender.email.domain.root_domain`	member	`amazon.com`
`sender.email.domain.root_domain`	member	`amazon.com.au`
`sender.email.domain.root_domain`	member	`amazon.co.uk`

20 more

`sender.email.domain.root_domain`	member	`amazon.de`
`sender.email.domain.root_domain`	member	`amazon.es`
`sender.email.domain.root_domain`	member	`amazon.fr`
`sender.email.domain.root_domain`	member	`amazon.it`
`sender.email.domain.root_domain`	member	`amazon.in`
`sender.email.domain.root_domain`	member	`amazon.lu`
`sender.email.domain.root_domain`	member	`amazonsellerservices.com`
`sender.email.domain.root_domain`	member	`amazon.ae`
`sender.email.domain.root_domain`	member	`amazon.sa`
`sender.email.domain.root_domain`	member	`amazon.cn`
`sender.email.domain.root_domain`	member	`amazon.ca`
`sender.email.domain.root_domain`	member	`amazon.com.mx`
`sender.email.domain.root_domain`	member	`amazon.com.br`
`sender.email.domain.root_domain`	member	`amazon.ph`
`sender.email.domain.root_domain`	member	`amazon.sg`
`sender.email.domain.root_domain`	member	`amazon.com.tr`
`sender.email.domain.root_domain`	member	`amazonpay.in`
`sender.email.domain.root_domain`	member	`amazonpay.com`
`sender.email.domain.root_domain`	member	`synchronybank.com`
`sender.email.domain.root_domain`	member	`aws.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)