Hunt for compromised browser extensions

Group by: ExtensionId, Id
Author: Robbe Van den Daele
Source: github.com/HybridBrothers/Hunting-Queries-Detection-Rules

This hunting rule can be used to find devices using known compromised browser extensions. It is created based on the threat researched linked in the reference section.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1176` Software Extensions

References

https://arstechnica.com/security/2025/01/dozens-of-backdoored-chrome-extensions-discovered-on-2-6-million-devices/

Rule body yaml

let extensions = datatable (Id:string, VulnVersion:string) [
    "nnpnnpemnckcfdebeekibpiijlicmpom", "2.0.1",
    "kkodiihpgodmdankclfibbiphjkfdenh", "1.16.2",
    "oaikpkmjciadfpddlpjjdapglcihgdle", "1.0.12",
    "dpggmcodlahmljkhlmpgpdcffdaoccni", "1.1.1",
    "acmfnomgphggonodopogfbmkneepfgnh", "4.00",
    "mnhffkhmpnefgklngfmlndmkimimbphc", "4.40",
    "cedgndijpacnfbdggppddacngjfdkaca", "0.0.11",
    "bbdnohkpnbkdkmnkddobeafboooinpla", "1.0.1",
    "egmennebgadmncfjafcemlecimkepcle", "2.2.7",
    "bibjgkidgpfbblifamdlkdlhgihmfohh", "0.1.3",
    "befflofjcniongenjmbkgkoljhgliihe", "2.13.0",
    "pkgciiiancapdlpcbppfkmeaieppikkk", "1.3.7",
    "llimhhconnjiflfimocjggfjdlmlhblm", "1.5.7",
    "oeiomhmbaapihbilkfkhmlajkeegnjhe", "3.18.0",
    "pajkjnmeojmbapicmbpliphjmcekeaac", "24.10.4",
    "ndlbedplllcgconngcnfmkadhokfaaln", "2.22.6",
    "epdjhgbipjpbbhoccdeipghoihibnfja", "1.4",
    "cplhlgabfijoiabgkigdafklbhhdkahj", "1.0.161",
    "jiofmdifioeejeilfkpegipdjiopiekl", "1.1.61",
    "hihblcmlaaademjlakdpicchbjnnnkbo", "3.0.2",
    "llimhhconnjiflfimocjggfjdlmlhblm", "1.5.7",
    "ekpkdmohpdnebfedjjfklhpefgpgaaji", "1.3",
    "epikoohpebngmakjinphfiagogjcnddm", "2.7.3",
    "miglaibdlgminlepgeifekifakochlka", "1.4.5",
    "eanofdhdfbcalhflpbdipkjjkoimeeod", "1.4.9",
    "ogbhbgkiojdollpjbhbamafmedkeockb", "1.8.1",
    "bgejafhieobnfpjlpcjjggoboebonfcg", "1.1.1",
    "igbodamhgjohafcenbcljfegbipdfjpk", "2.3",
    "mbindhfolmpijhodmgkloeeppmkhpmhc", "1.44",
    "hodiladlefdpcbemnbbcpclbmknkiaem", "3.1.3",
    "lbneaaedflankmgmfbmaplggbmjjmbae", "1.3.8",
    "eaijffijbobmnonfhilihbejadplhddo", "2.4",
    "hmiaoahjllhfgebflooeeefeiafpkfde", "1.0.0"
];
DeviceTvmBrowserExtensions
// Find devices using vulnerable extensions
| join kind=inner extensions on $left.ExtensionId == $right.Id
| extend IntVersion = parse_version(ExtensionVersion), IntVulnVursion = parse_version(VulnVersion)
| where IntVersion <= IntVulnVursion and IsActivated == "true"
// Join for more device info
| join kind=inner (
    DeviceInfo 
    | where Timestamp > ago(7d)
) on DeviceId
| distinct DeviceName, DeviceId, BrowserName, ExtensionName, ExtensionDescription, ExtensionVersion, ExtensionRisk, VulnVersion

Stages and Predicates

Let binding: `extensions`

let extensions = datatable (Id:string, VulnVersion:string) [
    "nnpnnpemnckcfdebeekibpiijlicmpom", "2.0.1",
    "kkodiihpgodmdankclfibbiphjkfdenh", "1.16.2",
    "oaikpkmjciadfpddlpjjdapglcihgdle", "1.0.12",
    "dpggmcodlahmljkhlmpgpdcffdaoccni", "1.1.1",
    "acmfnomgphggonodopogfbmkneepfgnh", "4.00",
    "mnhffkhmpnefgklngfmlndmkimimbphc", "4.40",
    "cedgndijpacnfbdggppddacngjfdkaca", "0.0.11",
    "bbdnohkpnbkdkmnkddobeafboooinpla", "1.0.1",
    "egmennebgadmncfjafcemlecimkepcle", "2.2.7",
    "bibjgkidgpfbblifamdlkdlhgihmfohh", "0.1.3",
    "befflofjcniongenjmbkgkoljhgliihe", "2.13.0",
    "pkgciiiancapdlpcbppfkmeaieppikkk", "1.3.7",
    "llimhhconnjiflfimocjggfjdlmlhblm", "1.5.7",
    "oeiomhmbaapihbilkfkhmlajkeegnjhe", "3.18.0",
    "pajkjnmeojmbapicmbpliphjmcekeaac", "24.10.4",
    "ndlbedplllcgconngcnfmkadhokfaaln", "2.22.6",
    "epdjhgbipjpbbhoccdeipghoihibnfja", "1.4",
    "cplhlgabfijoiabgkigdafklbhhdkahj", "1.0.161",
    "jiofmdifioeejeilfkpegipdjiopiekl", "1.1.61",
    "hihblcmlaaademjlakdpicchbjnnnkbo", "3.0.2",
    "llimhhconnjiflfimocjggfjdlmlhblm", "1.5.7",
    "ekpkdmohpdnebfedjjfklhpefgpgaaji", "1.3",
    "epikoohpebngmakjinphfiagogjcnddm", "2.7.3",
    "miglaibdlgminlepgeifekifakochlka", "1.4.5",
    "eanofdhdfbcalhflpbdipkjjkoimeeod", "1.4.9",
    "ogbhbgkiojdollpjbhbamafmedkeockb", "1.8.1",
    "bgejafhieobnfpjlpcjjggoboebonfcg", "1.1.1",
    "igbodamhgjohafcenbcljfegbipdfjpk", "2.3",
    "mbindhfolmpijhodmgkloeeppmkhpmhc", "1.44",
    "hodiladlefdpcbemnbbcpclbmknkiaem", "3.1.3",
    "lbneaaedflankmgmfbmaplggbmjjmbae", "1.3.8",
    "eaijffijbobmnonfhilihbejadplhddo", "2.4",
    "hmiaoahjllhfgebflooeeefeiafpkfde", "1.0.0"
];

Stage 1: `source`

DeviceTvmBrowserExtensions

Stage 2: `join`

| join kind=inner extensions on $left.ExtensionId == $right.Id

Stage 3: `extend`

| extend IntVersion = parse_version(ExtensionVersion), IntVulnVursion = parse_version(VulnVersion)

Stage 4: `where`

| where IntVersion <= IntVulnVursion and IsActivated == "true"

Stage 5: `join`

| join kind=inner (
    DeviceInfo 
    | where Timestamp > ago(7d)
) on DeviceId

Stage 6: `distinct`

| distinct DeviceName, DeviceId, BrowserName, ExtensionName, ExtensionDescription, ExtensionVersion, ExtensionRisk, VulnVersion

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`IntVersion`	le	`IntVulnVursion` transforms: `cased`
`IsActivated`	eq	`true` transforms: `cased`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`IntVersion`	`extend`
`IntVulnVursion`	`extend`

`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)

Hunt for compromised browser extensions

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: `extensions`

Stage 1: `source`

Stage 2: `join`

Stage 3: `extend`

Stage 4: `where`

Stage 5: `join`

Stage 6: `distinct`

Indicators

Output fields

Keyboard shortcuts

Search operators

Hunt for compromised browser extensions

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: extensions

Stage 1: source

Stage 2: join

Stage 3: extend

Stage 4: where

Stage 5: join

Stage 6: distinct

Indicators

Output fields

Let binding: `extensions`

Stage 1: `source`

Stage 2: `join`

Stage 3: `extend`

Stage 4: `where`

Stage 5: `join`

Stage 6: `distinct`