Credential Phishing: W-2 lure with inline SVG Windows logo

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

Detects inbound messages containing a link with W-2 display text and an inline SVG constructed from four colored rectangles approximating the Microsoft Windows logo. Threat actors use hand-crafted SVG elements rather than image attachments to bypass image-based detection and render a convincing Windows or Microsoft brand impersonation directly in the email body. The color matching uses fuzzy hex ranges to account for minor variations across campaigns.

Threat classification

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

Category	Values
Attack types	Credential Phishing
Tactics and techniques	Evasion, HTML smuggling, Social engineering

Event coverage

Message attribute
body.current_thread
body.html
type

Rule body MQL

type.inbound
// display text contains a reference to W2
and any(body.current_thread.links,
        regex.icontains(strings.replace_confusables(.display_text),
                        '(?:W|VV)\s*-?\s*2'
        )
)
// inline SVG that mimics the Windows logo
and regex.icontains(body.html.raw,
                    '<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[c-f][0-9a-f][0-3][0-9a-f][0-3][0-9a-f]">\s*<\/rect>\s*<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[0-3][0-9a-f][8-f][0-9a-f][2-6][0-9a-f]">\s*<\/rect>\s*<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[0-3][0-9a-f][5-9][0-9a-f][a-f][0-9a-f]">\s*<\/rect>\s*<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[c-f][0-9a-f][a-f][0-9a-f][0-3][0-9a-f]">\s*<\/rect>\s*<\/svg>\s*<\/td>'
)

Detection logic

Scope: inbound message.

inbound message
any of body.current_thread.links where:
- strings.replace_confusables(.display_text) matches '(?:W|VV)\\s*-?\\s*2'
body.html.raw matches '<rect x="\\d+" y="\\d+" width="\\d+" height="\\d+" fill="#[c-f][0-9a-f][0-3][0-9a-f][0-3][0-9a-f]">\\s*<\\/rect>\\s*<rect x="\\d+" y="\\d+" width="\\d+" height="\\d+" fill="#[0-3][0-9a-f][8-f][0-9a-f][2-6][0-9a-f]">\\s*<\\/rect>\\s*<rect x="\\d+" y="\\d+" width="\\d+" height="\\d+" fill="#[0-3][0-9a-f][5-9][0-9a-f][a-f][0-9a-f]">\\s*<\\/rect>\\s*<rect x="\\d+" y="\\d+" width="\\d+" height="\\d+" fill="#[c-f][0-9a-f][a-f][0-9a-f][0-3][0-9a-f]">\\s*<\\/rect>\\s*<\\/svg>\\s*<\\/td>'

Inspects: body.current_thread.links, body.current_thread.links[].display_text, body.html.raw, type.inbound. Sensors: regex.icontains, strings.replace_confusables.

Indicators matched (2)

Field	Match	Value
`regex.icontains`	regex	`(?:W\|VV)\s-?\s2`
`regex.icontains`	regex	`<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[c-f][0-9a-f][0-3][0-9a-f][0-3][0-9a-f]">\s<\/rect>\s<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[0-3][0-9a-f][8-f][0-9a-f][2-6][0-9a-f]">\s<\/rect>\s<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[0-3][0-9a-f][5-9][0-9a-f][a-f][0-9a-f]">\s<\/rect>\s<rect x="\d+" y="\d+" width="\d+" height="\d+" fill="#[c-f][0-9a-f][a-f][0-9a-f][0-3][0-9a-f]">\s<\/rect>\s<\/svg>\s*<\/td>`

`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)