Process Injection From Untrusted Process

Group by: DeviceId, InitiatingProcessFolderPath
Author: FalconForce
Source: github.com/FalconForceTeam/FalconFriday

This query searches for processes performing remote process injection via multiple API calls related to process injection. It filters out programs that inject into their own process or into a process from the same directory. It then finds suspicious processes based on the global prevalence.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1106` Native API
Privilege Escalation	`T1055.002` Process Injection: Portable Executable Injection
Stealth	`T1055.002` Process Injection: Portable Executable Injection

References

https://medium.com/falconforce/falconfriday-process-injection-and-malicious-cpl-files-0xff03-8ba1ee5da64?source=friends_link&sk=1ed3672c2e7961dac11c1472cb5757e8

Event coverage

Provider	Event/ActionType	Title
Sysmon	Event ID 8	CreateRemoteThread
Defender-DeviceEvents	CreateRemoteThreadApiCall	CreateRemoteThread API call
Defender-DeviceEvents	NtAllocateVirtualMemoryRemoteApiCall	Remote virtual memory allocation (NtAllocateVirtualMemory)
Defender-DeviceEvents	NtMapViewOfSectionRemoteApiCall	Remote section map (NtMapViewOfSection)
Defender-DeviceEvents	QueueUserApcRemoteApiCall	Remote APC queued (QueueUserApc)
Defender-DeviceEvents	SetThreadContextRemoteApiCall	Remote thread context change (SetThreadContext)
Threat-Intelligence	Event ID 1	Remote Virtual Memory Allocation
Threat-Intelligence	Event ID 3	Remote Section Map
Threat-Intelligence	Event ID 4	Remote APC Queue
Threat-Intelligence	Event ID 5	Remote Thread Context Change

Rule body kusto

let timeframe = 2*1h;
let default_global_prevalence = 0;
let AllProcessInjectionEvents = materialize(
    DeviceEvents
    | where ingestion_time() >= ago(timeframe)
    | where ActionType in~ ("QueueUserApcRemoteApiCall","NtAllocateVirtualMemoryRemoteApiCall", "CreateRemoteThreadApiCall", "SetThreadContextRemoteApiCall", "NtMapViewOfSectionRemoteApiCall") and ProcessId != InitiatingProcessId
    | extend InitiatingProcessSHA1=tolower(InitiatingProcessSHA1)
    | where not(InitiatingProcessFolderPath startswith FolderPath) // Exclude injection into processes in the same directory.
);
let SuspiciousProcessInjectionEvents = (
    AllProcessInjectionEvents
    | where not(isempty(InitiatingProcessSHA1)) // Only with a valid SHA1.
    | summarize MachineCount=dcount(DeviceId) by InitiatingProcessSHA1
    // Take 1000 of the most unique hashes, as files with high prevalence are very likely to be legitimately signed.
    | top 1000 by MachineCount asc
    | invoke FileProfile(InitiatingProcessSHA1, 1000)
    | where not(ProfileAvailability =~ "Error")
    | where coalesce(GlobalPrevalence,default_global_prevalence) < 200 or ((isempty(Signer) or not(IsCertificateValid)) and coalesce(GlobalPrevalence,default_global_prevalence) < 500)
);
AllProcessInjectionEvents
| lookup kind=inner SuspiciousProcessInjectionEvents on InitiatingProcessSHA1
// Work around the Defender limitation where FolderPath for CreateRemoteThreadApiCall does not contain FileName where it does for other events.
| extend InjectionTarget=strcat(FolderPath,@"\",FileName)
// Begin environment-specific filter.
// End environment-specific filter.
| summarize arg_min(Timestamp, *), InjectionTargets=make_set(InjectionTarget) by DeviceId, InitiatingProcessFolderPath // Show only the first invocation per device.
| extend InjectionSource=InitiatingProcessFolderPath, InjectionCommandLine=InitiatingProcessCommandLine
| project-reorder Timestamp, InjectionSource, InjectionCommandLine, InjectionTargets

Stages and Predicates

Parameters

let timeframe = 2*1h;
let default_global_prevalence = 0;

Let binding: `SuspiciousProcessInjectionEvents`

let SuspiciousProcessInjectionEvents = (
    AllProcessInjectionEvents
    | where not(isempty(InitiatingProcessSHA1))
    | summarize MachineCount=dcount(DeviceId) by InitiatingProcessSHA1
    | top 1000 by MachineCount asc
    | invoke FileProfile(InitiatingProcessSHA1, 1000)
    | where not(ProfileAvailability =~ "Error")
    | where coalesce(GlobalPrevalence,default_global_prevalence) < 200 or ((isempty(Signer) or not(IsCertificateValid)) and coalesce(GlobalPrevalence,default_global_prevalence) < 500)
);

Derived from default_global_prevalence, AllProcessInjectionEvents.

The stages below define let AllProcessInjectionEvents (the rule's main pipeline source).

Stage 1: `source`

DeviceEvents

Stage 2: `where`

| where ingestion_time() >= ago(timeframe)

Stage 3: `where`

| where ActionType in~ ("QueueUserApcRemoteApiCall","NtAllocateVirtualMemoryRemoteApiCall", "CreateRemoteThreadApiCall", "SetThreadContextRemoteApiCall", "NtMapViewOfSectionRemoteApiCall") and ProcessId != InitiatingProcessId

Stage 4: `extend`

| extend InitiatingProcessSHA1=tolower(InitiatingProcessSHA1)

Stage 5: `where`

| where not(InitiatingProcessFolderPath startswith FolderPath)

The stages below run on AllProcessInjectionEvents (the outer pipeline).

Stage 6: `kusto:lookup`

AllProcessInjectionEvents
| lookup kind=inner SuspiciousProcessInjectionEvents on InitiatingProcessSHA1

Stage 7: `extend`

| extend InjectionTarget=strcat(FolderPath,@"\",FileName)

Stage 8: `summarize`

| summarize arg_min(Timestamp, *), InjectionTargets=make_set(InjectionTarget) by DeviceId, InitiatingProcessFolderPath

Stage 9: `extend`

| extend InjectionSource=InitiatingProcessFolderPath, InjectionCommandLine=InitiatingProcessCommandLine

Stage 10: `project-reorder`

| project-reorder Timestamp, InjectionSource, InjectionCommandLine, InjectionTargets

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`InitiatingProcessFolderPath`	starts_with	`FolderPath`

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`	in	`CreateRemoteThreadApiCall` `NtAllocateVirtualMemoryRemoteApiCall` `NtMapViewOfSectionRemoteApiCall` `QueueUserApcRemoteApiCall` `SetThreadContextRemoteApiCall`
`ProcessId`	ne	`InitiatingProcessId` 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
`DeviceId`	`summarize`
`InitiatingProcessFolderPath`	`summarize`
`InjectionTargets`	`summarize`
`InjectionCommandLine`	`extend`
`InjectionSource`	`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
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`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)

Process Injection From Untrusted Process

MITRE ATT&CK coverage

References

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `SuspiciousProcessInjectionEvents`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `kusto:lookup`

Stage 7: `extend`

Stage 8: `summarize`

Stage 9: `extend`

Stage 10: `project-reorder`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Process Injection From Untrusted Process

MITRE ATT&CK coverage

References

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: SuspiciousProcessInjectionEvents

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: where

Stage 6: kusto:lookup

Stage 7: extend

Stage 8: summarize

Stage 9: extend

Stage 10: project-reorder

Exclusions

Indicators

Output fields

Let binding: `SuspiciousProcessInjectionEvents`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `kusto:lookup`

Stage 7: `extend`

Stage 8: `summarize`

Stage 9: `extend`

Stage 10: `project-reorder`