Open redirect: YouTube

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

Looks for use of the YouTube open redirect coming from someone other than YouTube.

Threat classification

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

Category	Values
Attack types	Credential Phishing, Malware/Ransomware
Tactics and techniques	Open redirect

Event coverage

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

Rule body MQL

type.inbound
and (
  any(body.links,
      .href_url.domain.sld == "youtube"
      and (
        strings.icontains(.href_url.url, "attribution_link?")
        or .href_url.path == "/redirect"
      )
  )
  or any(attachments,
         (
           .file_extension in~ $file_extensions_macros
           or .file_extension in~ $file_extensions_common_archives
           or (
             .file_extension is null
             and .file_type == "unknown"
             and .content_type == "application/octet-stream"
             and .size < 100000000
           )
         )
         and any(file.oletools(.).relationships,
                 .name == "hyperlink"
                 and .target_url.domain.sld == "youtube"
                 and (
                   strings.icontains(.target_url.path, "attribution_link?")
                   or .target_url.path == "/redirect"
                 )
         )
  )
)
and headers.auth_summary.dmarc.details.from.root_domain == "youtube.com"

// 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().solicited
  or profile.by_sender().any_messages_malicious_or_spam
)

Detection logic

Scope: inbound message.

Looks for use of the YouTube open redirect coming from someone other than YouTube.

inbound message
any of:
- any of body.links where all hold:
  - .href_url.domain.sld is 'youtube'
  - any of:
    
    .href_url.url contains 'attribution_link?'
    .href_url.path is '/redirect'
- any of attachments where all hold:
  - any of:
    
    .file_extension in $file_extensions_macros
    .file_extension in $file_extensions_common_archives
    all of:
    
    .file_extension is missing
    .file_type is 'unknown'
    .content_type is 'application/octet-stream'
    .size < 100000000
  - any of file.oletools(.).relationships where all hold:
    
    .name is 'hyperlink'
    .target_url.domain.sld is 'youtube'
    any of:
    
    .target_url.path contains 'attribution_link?'
    .target_url.path is '/redirect'
headers.auth_summary.dmarc.details.from.root_domain is 'youtube.com'
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
any of:
- not:
  - profile.by_sender().solicited
- profile.by_sender().any_messages_malicious_or_spam

Inspects: attachments[].content_type, attachments[].file_extension, attachments[].file_type, attachments[].size, body.links, body.links[].href_url.domain.sld, body.links[].href_url.path, body.links[].href_url.url, headers.auth_summary.dmarc.details.from.root_domain, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: file.oletools, profile.by_sender, strings.icontains. Reference lists: $file_extensions_common_archives, $file_extensions_macros, $high_trust_sender_root_domains.

Indicators matched (9)

Field	Match	Value
`body.links[].href_url.domain.sld`	equals	`youtube`
`strings.icontains`	substring	`attribution_link?`
`body.links[].href_url.path`	equals	`/redirect`
`attachments[].file_type`	equals	`unknown`
`attachments[].content_type`	equals	`application/octet-stream`
`file.oletools(attachments[]).relationships[].name`	equals	`hyperlink`
`file.oletools(attachments[]).relationships[].target_url.domain.sld`	equals	`youtube`
`file.oletools(attachments[]).relationships[].target_url.path`	equals	`/redirect`
`headers.auth_summary.dmarc.details.from.root_domain`	equals	`youtube.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)

Open redirect: YouTube

Threat classification

Event coverage

Rule body MQL

Detection logic

Indicators matched (9)

Keyboard shortcuts

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