Masquerading Renamed executables of interest

Author: FalconForce
Source: github.com/FalconForceTeam/FalconFriday

This query searches for the original file name of a set of binaries that is known to be used by attackers. The OriginalFileName field is then matched to the actual file name. Where there isn't a match the results are returned, indicating the file has been renamed. The original file name field is derived from the PE header of the executable, which is the name of the binary during compilation.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1036.003` Masquerading: Rename Legitimate Utilities

References

https://attack.mitre.org/techniques/T1036/003/

Event coverage

Provider	Event/ActionType	Title
Sysmon	Event ID 1	Process creation
Security-Auditing	Event ID 4688	A new process has been created.
Defender-DeviceProcessEvents	ProcessCreated	Process created

Rule body kusto

let timeframe = 2*1h;
let lolbins = dynamic(["at.exe", "atbroker.exe", "bash.exe", "bitsadmin.exe", "certreq.exe", "certutil.exe", "cmd.exe", "cmdkey.exe", "cmstp.exe", "control.exe", "csc.exe", "cscript.exe", "desktopimgdownldr.exe", "dfsvc.exe", "diantz.exe", "diskshadow.exe", "dnscmd.exe", "esentutl.exe", "eventvwr.exe", "expand.exe", "extexport.exe", "extrac32.exe", "findstr.exe", "forfiles.exe", "ftp.exe", "gfxdownloadwrapper.exe", "gpscript.exe", "hh.exe", "ie4uinit.exe", "ieexec.exe", "ilasm.exe", "infdefaultinstall.exe", "installutil.exe", "jsc.exe", "makecab.exe", "mavinject.exe", "microsoft.workflow.compiler.exe", "mmc.exe", "mpcmdrun.exe", "msbuild.exe", "msconfig.exe", "msdt.exe", "mshta.exe", "msiexec.exe", "netsh.exe", "odbcconf.exe", "pcalua.exe", "pcwrun.exe", "pktmon.exe", "presentationhost.exe", "print.exe", "psr.exe", "rasautou.exe", "reg.exe", "regasm.exe", "regedit.exe", "regini.exe", "register-cimprovider.exe", "regsvcs.exe", "regsvr32.exe", "replace.exe", "rpcping.exe", "rundll32.exe", "runonce.exe", "runscripthelper.exe", "sc.exe", "schtasks.exe", "scriptrunner.exe", "syncappvpublishingserver.exe", "ttdinject.exe", "tttracer.exe", "vbc.exe", "verclsid.exe", "wab.exe", "wmic.exe", "wscript.exe", "wsreset.exe", "xwizard.exe", "agentexecutor.exe", "appvlp.exe", "bginfo.exe", "cdb.exe", "csi.exe", "devtoolslauncher.exe", "dnx.exe", "dotnet.exe", "dxcap.exe", "excel.exe", "mftrace.exe", "msdeploy.exe", "msxsl.exe", "ntdsutil.exe", "powerpnt.exe", "rcsi.exe", "sqldumper.exe", "sqlps.exe", "sqltoolsps.exe", "squirrel.exe", "te.exe", "tracker.exe", "vsjitdebugger.exe", "winword.exe", "wsl.exe", "powershell.exe", "pwsh.exe"]);
let binaries_of_interest = dynamic(["net.exe", "net1.exe", "whoami.exe", "ipconfig.exe", "tasklist.exe", "quser.exe", "tracert.exe", "route.exe", "runas.exe", "klist.exe", "wevtutil.exe", "wmiprvse.exe", "powershell.exe", "bash.exe", "qwinsta.exe", "rwinsta.exe", "replace.exe", "findstr.exe", "icacls.exe", "cacls.exe", "xcopy.exe", "robocopy.exe", "takeown.exe", "vssadmin.exe", "nltest.exe", "nltestk.exe", "sctasks.exe", "nbtstat.exe", "nbtinfo.exe", "mofcomp.exe", "nltestrk.exe", "dnscmd.exe", "registercimprovider.exe", "registercimprovider2.exe", "procdump", "ru.exe", "pspasswd.exe", "psexec.c", "psexec.exe", "pslist.exe", "regsize", "pskill.exe", "pkill.exe", "wsmprovhost.exe", "fltmc.exe", "sdbinst.exe"]);
// Merge both lists into one reference list.
let original_file_name_set=array_concat(lolbins,binaries_of_interest);
DeviceProcessEvents
| where ingestion_time() >= ago(timeframe)
| where ActionType =~ "ProcessCreated"
| extend process_name=tolower(FileName)
| extend original_file_name=tolower(ProcessVersionInfoOriginalFileName)
| where original_file_name in~ (original_file_name_set)
| where original_file_name != ""
// Filter some known mismatches between PE header FileName and the binary FileName.
| where not(process_name=~"schtasks.exe" and original_file_name=~"schtasks.exe" and (FolderPath=~@"C:\Windows\System32\schtasks.exe" or FolderPath=~@"C:\Windows\SysWOW64\schtasks.exe"))
| where not(process_name=~"nbtstat.exe" and original_file_name=~"nbtinfo.exe" and FolderPath=~@"C:\Windows\System32\nbtstat.exe")
| where not(process_name=~"bginfo64.exe" and original_file_name=~"bginfo.exe" and (FolderPath=~@"C:\Windows\System32\Bginfo64.exe" or FolderPath =~@"C:\Program Files\SysInternals BGInfo\Bginfo64.exe"))
// Filter MS Excel file format converter.
| where not(process_name=~"excelcnv.exe" and original_file_name=~"excel.exe" and (FolderPath startswith @"C:\Program Files\Microsoft Office Web Apps\ExcelServicesEcs\" or FolderPath  startswith @"C:\Program Files\Microsoft Office\" or FolderPath startswith @"C:\Program Files (x86)\Microsoft Office\"))
// Optionally filter this (when psexec is actually common in your environment).
| where not(process_name=~"psexec.exe" and original_file_name=~"psexec.c")
| where not(process_name=~"psexec64.exe" and original_file_name=~"psexec.c")
| where process_name != original_file_name
| project Timestamp,DeviceName,DeviceId,AccountName,process_name, original_file_name, FolderPath, ProcessCommandLine, InitiatingProcessFileName, InitiatingProcessVersionInfoOriginalFileName, InitiatingProcessCommandLine, InitiatingProcessParentFileName, ReportId, InitiatingProcessAccountUpn
// Begin environment-specific filter.
// End environment-specific filter.

Stages and Predicates

Parameters

let timeframe = 2*1h;
let original_file_name_set = array_concat(lolbins,binaries_of_interest);

Let binding: `lolbins`

let lolbins = dynamic(["at.exe", "atbroker.exe", "bash.exe", "bitsadmin.exe", "certreq.exe", "certutil.exe", "cmd.exe", "cmdkey.exe", "cmstp.exe", "control.exe", "csc.exe", "cscript.exe", "desktopimgdownldr.exe", "dfsvc.exe", "diantz.exe", "diskshadow.exe", "dnscmd.exe", "esentutl.exe", "eventvwr.exe", "expand.exe", "extexport.exe", "extrac32.exe", "findstr.exe", "forfiles.exe", "ftp.exe", "gfxdownloadwrapper.exe", "gpscript.exe", "hh.exe", "ie4uinit.exe", "ieexec.exe", "ilasm.exe", "infdefaultinstall.exe", "installutil.exe", "jsc.exe", "makecab.exe", "mavinject.exe", "microsoft.workflow.compiler.exe", "mmc.exe", "mpcmdrun.exe", "msbuild.exe", "msconfig.exe", "msdt.exe", "mshta.exe", "msiexec.exe", "netsh.exe", "odbcconf.exe", "pcalua.exe", "pcwrun.exe", "pktmon.exe", "presentationhost.exe", "print.exe", "psr.exe", "rasautou.exe", "reg.exe", "regasm.exe", "regedit.exe", "regini.exe", "register-cimprovider.exe", "regsvcs.exe", "regsvr32.exe", "replace.exe", "rpcping.exe", "rundll32.exe", "runonce.exe", "runscripthelper.exe", "sc.exe", "schtasks.exe", "scriptrunner.exe", "syncappvpublishingserver.exe", "ttdinject.exe", "tttracer.exe", "vbc.exe", "verclsid.exe", "wab.exe", "wmic.exe", "wscript.exe", "wsreset.exe", "xwizard.exe", "agentexecutor.exe", "appvlp.exe", "bginfo.exe", "cdb.exe", "csi.exe", "devtoolslauncher.exe", "dnx.exe", "dotnet.exe", "dxcap.exe", "excel.exe", "mftrace.exe", "msdeploy.exe", "msxsl.exe", "ntdsutil.exe", "powerpnt.exe", "rcsi.exe", "sqldumper.exe", "sqlps.exe", "sqltoolsps.exe", "squirrel.exe", "te.exe", "tracker.exe", "vsjitdebugger.exe", "winword.exe", "wsl.exe", "powershell.exe", "pwsh.exe"]);

Let binding: `binaries_of_interest`

let binaries_of_interest = dynamic(["net.exe", "net1.exe", "whoami.exe", "ipconfig.exe", "tasklist.exe", "quser.exe", "tracert.exe", "route.exe", "runas.exe", "klist.exe", "wevtutil.exe", "wmiprvse.exe", "powershell.exe", "bash.exe", "qwinsta.exe", "rwinsta.exe", "replace.exe", "findstr.exe", "icacls.exe", "cacls.exe", "xcopy.exe", "robocopy.exe", "takeown.exe", "vssadmin.exe", "nltest.exe", "nltestk.exe", "sctasks.exe", "nbtstat.exe", "nbtinfo.exe", "mofcomp.exe", "nltestrk.exe", "dnscmd.exe", "registercimprovider.exe", "registercimprovider2.exe", "procdump", "ru.exe", "pspasswd.exe", "psexec.c", "psexec.exe", "pslist.exe", "regsize", "pskill.exe", "pkill.exe", "wsmprovhost.exe", "fltmc.exe", "sdbinst.exe"]);

Stage 1: `source`

DeviceProcessEvents

Stage 2: `where`

| where ingestion_time() >= ago(timeframe)

Stage 3: `where`

| where ActionType =~ "ProcessCreated"

Stage 4: `extend`

| extend process_name=tolower(FileName)

Stage 5: `extend`

| extend original_file_name=tolower(ProcessVersionInfoOriginalFileName)

Stage 6: `where`

| where original_file_name in~ (original_file_name_set)

Stage 7: `where`

| where original_file_name != ""

Stage 8: `where`

| where not(process_name=~"schtasks.exe" and original_file_name=~"schtasks.exe" and (FolderPath=~@"C:\Windows\System32\schtasks.exe" or FolderPath=~@"C:\Windows\SysWOW64\schtasks.exe"))

Stage 9: `where`

| where not(process_name=~"nbtstat.exe" and original_file_name=~"nbtinfo.exe" and FolderPath=~@"C:\Windows\System32\nbtstat.exe")

Stage 10: `where`

| where not(process_name=~"bginfo64.exe" and original_file_name=~"bginfo.exe" and (FolderPath=~@"C:\Windows\System32\Bginfo64.exe" or FolderPath =~@"C:\Program Files\SysInternals BGInfo\Bginfo64.exe"))

Stage 11: `where`

| where not(process_name=~"excelcnv.exe" and original_file_name=~"excel.exe" and (FolderPath startswith @"C:\Program Files\Microsoft Office Web Apps\ExcelServicesEcs\" or FolderPath  startswith @"C:\Program Files\Microsoft Office\" or FolderPath startswith @"C:\Program Files (x86)\Microsoft Office\"))

Stage 12: `where`

| where not(process_name=~"psexec.exe" and original_file_name=~"psexec.c")

Stage 13: `where`

| where not(process_name=~"psexec64.exe" and original_file_name=~"psexec.c")

Stage 14: `where`

| where process_name != original_file_name

Stage 15: `project`

| project Timestamp,DeviceName,DeviceId,AccountName,process_name, original_file_name, FolderPath, ProcessCommandLine, InitiatingProcessFileName, InitiatingProcessVersionInfoOriginalFileName, InitiatingProcessCommandLine, InitiatingProcessParentFileName, ReportId, InitiatingProcessAccountUpn

Exclusions

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

Field	Kind	Excluded values
`FolderPath`	eq	`C:\Windows\SysWOW64\schtasks.exe`
`FolderPath`	eq	`C:\Windows\System32\schtasks.exe`
`original_file_name`	eq	`schtasks.exe`
`process_name`	eq	`schtasks.exe`
`FolderPath`	eq	`C:\Windows\System32\nbtstat.exe`
`original_file_name`	eq	`nbtinfo.exe`
`process_name`	eq	`nbtstat.exe`
`FolderPath`	eq	`C:\Program Files\SysInternals BGInfo\Bginfo64.exe`
`FolderPath`	eq	`C:\Windows\System32\Bginfo64.exe`
`original_file_name`	eq	`bginfo.exe`
`process_name`	eq	`bginfo64.exe`
`FolderPath`	starts_with	`C:\Program Files (x86)\Microsoft Office\`
`FolderPath`	starts_with	`C:\Program Files\Microsoft Office Web Apps\ExcelServicesEcs\`
`FolderPath`	starts_with	`C:\Program Files\Microsoft Office\`
`original_file_name`	eq	`excel.exe`
`process_name`	eq	`excelcnv.exe`
`original_file_name`	eq	`psexec.c`
`process_name`	eq	`psexec.exe`
`original_file_name`	eq	`psexec.c`
`process_name`	eq	`psexec64.exe`

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`	eq	`ProcessCreated` corpus 10 (kusto 10)
`original_file_name`	in	`original_file_name_set`
`process_name`	ne	`original_file_name` 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
`AccountName`	`project`
`DeviceId`	`project`
`DeviceName`	`project`
`FolderPath`	`project`
`InitiatingProcessAccountUpn`	`project`
`InitiatingProcessCommandLine`	`project`
`InitiatingProcessFileName`	`project`
`InitiatingProcessParentFileName`	`project`
`InitiatingProcessVersionInfoOriginalFileName`	`project`
`ProcessCommandLine`	`project`
`ReportId`	`project`
`Timestamp`	`project`
`original_file_name`	`project`
`process_name`	`project`

`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)

Masquerading Renamed executables of interest

MITRE ATT&CK coverage

References

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `lolbins`

Let binding: `binaries_of_interest`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `extend`

Stage 6: `where`

Stage 7: `where`

Stage 8: `where`

Stage 9: `where`

Stage 10: `where`

Stage 11: `where`

Stage 12: `where`

Stage 13: `where`

Stage 14: `where`

Stage 15: `project`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Masquerading Renamed executables of interest

MITRE ATT&CK coverage

References

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: lolbins

Let binding: binaries_of_interest

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: extend

Stage 6: where

Stage 7: where

Stage 8: where

Stage 9: where

Stage 10: where

Stage 11: where

Stage 12: where

Stage 13: where

Stage 14: where

Stage 15: project

Exclusions

Indicators

Output fields

Let binding: `lolbins`

Let binding: `binaries_of_interest`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `extend`

Stage 6: `where`

Stage 7: `where`

Stage 8: `where`

Stage 9: `where`

Stage 10: `where`

Stage 11: `where`

Stage 12: `where`

Stage 13: `where`

Stage 14: `where`

Stage 15: `project`