TEARDROP memory-only dropper

Status: available
Severity: high
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

Identifies SolarWinds TEARDROP memory-only dropper IOCs in Window's defender Exploit Guard activity References: - https://www.fireeye.com/blog/threat-research/2020/12/evasive-attacker-leverages-solarwinds-supply-chain-compromises-with-sunburst-backdoor.html - https://gist.github.com/olafhartong/71ffdd4cab4b6acd5cbcd1a0691ff82f

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter
Persistence	`T1543` Create or Modify System Process
Stealth	`T1027` Obfuscated Files or Information

Event coverage

Provider	ActionType	Title
Defender-DeviceEvents	any	Defender event (any)

Rule body kusto

id: 738702fd-0a66-42c7-8586-e30f0583f8fe
name: TEARDROP memory-only dropper
description: |
  Identifies SolarWinds TEARDROP memory-only dropper IOCs in Window's defender Exploit Guard activity
  References:
  - https://www.fireeye.com/blog/threat-research/2020/12/evasive-attacker-leverages-solarwinds-supply-chain-compromises-with-sunburst-backdoor.html
  - https://gist.github.com/olafhartong/71ffdd4cab4b6acd5cbcd1a0691ff82f
severity: High
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceEvents
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Execution
  - Persistence
  - DefenseEvasion
relevantTechniques:
  - T1543
  - T1059
  - T1027
tags:
  - Sunburst
  - Solorigate
  - NOBELIUM
query:  |
  DeviceEvents
  | where ActionType has "ExploitGuardNonMicrosoftSignedBlocked"
  | where InitiatingProcessFileName has "svchost.exe" and FileName has "NetSetupSvc.dll"
  | extend HashAlgorithm = "SHA1"
  | extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName 
        columnName: DeviceName
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: HostNameDomain
  - entityType: Account
    fieldMappings:
      - identifier: FullName 
        columnName: InitiatingProcessAccountUpn
      - identifier: Name
        columnName: InitiatingProcessAccountName
      - identifier: UPNSuffix
        columnName: InitiatingProcessAccountDomain
  - entityType: FileHash
    fieldMappings:
      - identifier: Algorithm
        columnName: HashAlgorithm
      - identifier: Value
        columnName: InitiatingProcessSHA1
version: 1.0.6
kind: Scheduled

Stages and Predicates

Stage 1: `source`

DeviceEvents

Stage 2: `where`

| where ActionType has "ExploitGuardNonMicrosoftSignedBlocked"

Stage 3: `where`

| where InitiatingProcessFileName has "svchost.exe" and FileName has "NetSetupSvc.dll"

Stage 4: `extend` (3 consecutive steps)

| extend HashAlgorithm = "SHA1"
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)

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
`ActionType`	match	`ExploitGuardNonMicrosoftSignedBlocked` transforms: `term`
`FileName`	match	`NetSetupSvc.dll` transforms: `term`
`InitiatingProcessFileName`	match	`svchost.exe` transforms: `term`

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
`HashAlgorithm`	`extend`
`DomainIndex`	`extend`
`HostName`	`extend`
`HostNameDomain`	`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)

TEARDROP memory-only dropper

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend` (3 consecutive steps)

Indicators

Output fields

Keyboard shortcuts

Search operators

TEARDROP memory-only dropper

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend (3 consecutive steps)

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend` (3 consecutive steps)