# [CRIT] Tracing Digital Intent: New MacOS Tahoe 26 Artifact Discovered

**Source:** Unit 42 (Palo Alto)
**Published:** 2026-06-12
**Article:** https://unit42.paloaltonetworks.com/new-macos-artifact-discovered/

## Threat Profile

Threat Research Center 
Insights 
General 
General 
Tracing Digital Intent: New MacOS Tahoe 26 Artifact Discovered 
3 min read 
By: Chip Riley 
Published: June 12, 2026 
Categories: General 
Insights 
Tags: Digital forensics 
MacOS 
Surfacing a New Artifact 
Forensic examiners are constantly hunting for data that reveals not just what happened on a system, but the user's intent behind it. With the release of macOS Tahoe 26, a new artifact has surfaced that provides exactly this level of granular…

## Indicators of Compromise (high-fidelity only)

- _No high-fidelity IOCs in the RSS summary._ If the source publishes a technical write-up with defanged IOCs in the body, those would be picked up automatically on the next pipeline run.

## MITRE ATT&CK Techniques

- **T1566.002** — Spearphishing Link
- **T1204.001** — User Execution: Malicious Link
- **T1059.001** — PowerShell
- **T1566.001** — Spearphishing Attachment
- **T1204.002** — User Execution: Malicious File
- **T1059.005** — Visual Basic
- **T1218** — System Binary Proxy Execution
- **T1566.004** — Phishing: Spearphishing Voice
- **T1566** — Phishing
- **T1219** — Remote Access Software
- **T1195.002** — Compromise Software Supply Chain
- **T1070.004** — File Deletion
- **T1485** — Data Destruction
- **T1005** — Data from Local System
- **T1217** — Browser Information Discovery
- **T1083** — File and Directory Discovery

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Anti-forensic deletion/tampering of macOS Tahoe 26 App.MenuItem Biome stream

`UC_15_7` · phase: **actions** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Filesystem.process_name) as process_name values(Filesystem.process_path) as process_path values(Filesystem.user) as user from datamodel=Endpoint.Filesystem where Filesystem.action IN ("deleted","modified","renamed") AND Filesystem.file_path="*/Library/Biome/streams/restricted/App.MenuItem/*" by Filesystem.dest Filesystem.file_path Filesystem.file_name | `drop_dm_object_name(Filesystem)` | where NOT match(process_path,"(?i)/usr/libexec/biomed|/System/Library/|/usr/sbin/spindump") | convert ctime(firstTime) ctime(lastTime)
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(7d)
| where FolderPath has "/Library/Biome/streams/restricted/App.MenuItem"
| where ActionType in ("FileDeleted","FileRenamed","FileModified")
| where InitiatingProcessFileName !in~ ("biomed","biomesyncd","BiomeAgent","runningboardd","launchd")
| where InitiatingProcessFolderPath !startswith "/System/Library/"
| where InitiatingProcessFolderPath !startswith "/usr/libexec/"
| project Timestamp, DeviceName, InitiatingProcessAccountName, ActionType, FolderPath, FileName, InitiatingProcessFileName, InitiatingProcessFolderPath, InitiatingProcessCommandLine, InitiatingProcessParentFileName, SHA256
| order by Timestamp desc
```

### Non-forensic process bulk-reading the App.MenuItem Biome stream

`UC_15_8` · phase: **actions** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Filesystem.file_path) as paths from datamodel=Endpoint.Filesystem where Filesystem.action="read" AND Filesystem.file_path="*/Library/Biome/streams/restricted/App.MenuItem/*" by Filesystem.dest Filesystem.process_name Filesystem.process_path Filesystem.user | `drop_dm_object_name(Filesystem)` | where NOT match(process_path,"(?i)/usr/libexec/biomed|/System/Library/|/Applications/Xcode\.app/") | where count > 1 | convert ctime(firstTime) ctime(lastTime)
```

**Defender KQL:**
```kql
let SuspectReads = DeviceFileEvents
  | where Timestamp > ago(7d)
  | where FolderPath has "/Library/Biome/streams/restricted/App.MenuItem"
  | where ActionType in ("FileCreated","FileModified","FileRenamed")
  | summarize Touches = count() by DeviceId, DeviceName, InitiatingProcessId, InitiatingProcessFileName, InitiatingProcessFolderPath, InitiatingProcessCommandLine, InitiatingProcessAccountName, bin(Timestamp, 10m);
let ProcessReads = DeviceProcessEvents
  | where Timestamp > ago(7d)
  | where ProcessCommandLine has_any ("/Library/Biome/streams/restricted/App.MenuItem","ccl_segb_cli.py","ccl-segb","App.MenuItem/local")
  | where FileName !in~ ("biomed","biomesyncd","BiomeAgent")
  | project Timestamp, DeviceId, DeviceName, AccountName, FileName, FolderPath, ProcessCommandLine, InitiatingProcessFileName, InitiatingProcessCommandLine, SHA256;
union SuspectReads, ProcessReads
| where InitiatingProcessFileName !in~ ("biomed","biomesyncd","BiomeAgent","mdworker","mds_stores","Spotlight","backupd","tmutil")
| order by Timestamp desc
```

### Phishing-link click correlated to endpoint execution

`UC_PHISH_LINK` · phase: **delivery** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Phishing-link click that drives endpoint execution within 60s ```
| tstats `summariesonly` earliest(_time) AS click_time
    from datamodel=Web
    where Web.action="allowed"
    by Web.src, Web.user, Web.dest, Web.url
| `drop_dm_object_name(Web)`
| rename user AS recipient, dest AS clicked_domain, url AS clicked_url
| join type=inner recipient
    [| tstats `summariesonly` count
         from datamodel=Email.All_Email
         where All_Email.action="delivered" AND All_Email.url!="-"
         by All_Email.recipient, All_Email.src_user, All_Email.url, All_Email.subject
     | `drop_dm_object_name(All_Email)`
     | rex field=url "https?://(?<email_domain>[^/]+)"
     | rename recipient AS recipient]
| join type=inner src
    [| tstats `summariesonly` earliest(_time) AS exec_time
         values(Processes.process) AS exec_cmd, values(Processes.process_name) AS exec_proc
         from datamodel=Endpoint.Processes
         where Processes.parent_process_name IN ("chrome.exe","msedge.exe","firefox.exe",
                                                   "outlook.exe","brave.exe","arc.exe")
           AND Processes.process_name IN ("powershell.exe","pwsh.exe","cmd.exe","mshta.exe",
                                            "rundll32.exe","regsvr32.exe","wscript.exe",
                                            "cscript.exe","bitsadmin.exe","certutil.exe",
                                            "curl.exe","wget.exe")
         by Processes.dest, Processes.user
     | `drop_dm_object_name(Processes)`
     | rename dest AS src]
| eval delta_sec = exec_time - click_time
| where delta_sec >= 0 AND delta_sec <= 60
| table click_time, exec_time, delta_sec, recipient, src, src_user, subject,
        clicked_domain, clicked_url, exec_proc, exec_cmd
| sort - click_time
```

**Defender KQL:**
```kql
// Phishing-link click that drives endpoint execution within 60s.
// Far higher fidelity than "every clicked URL" — most legitimate clicks
// never spawn a non-browser child process, so the join eliminates the
// 99% of noise that makes a raw click query unactionable.
let LookbackDays = 7d;
let SuspectClicks = UrlClickEvents
    | where Timestamp > ago(LookbackDays)
    | where AccountName !endswith "$"
    | where ActionType in ("ClickAllowed","ClickedThrough")
    | join kind=inner (
        EmailEvents
        | where Timestamp > ago(LookbackDays)
        | where DeliveryAction == "Delivered"
        | where EmailDirection == "Inbound"
        | project NetworkMessageId, Subject, SenderFromAddress, SenderFromDomain,
                  RecipientEmailAddress, EmailTimestamp = Timestamp
      ) on NetworkMessageId
    | join kind=leftouter (
        EmailUrlInfo | project NetworkMessageId, Url, UrlDomain
      ) on NetworkMessageId, Url
    | project ClickTime = Timestamp, AccountUpn, IPAddress, Url, UrlDomain,
              Subject, SenderFromAddress, SenderFromDomain, RecipientEmailAddress,
              ActionType;
// Correlate to a non-browser child process spawned within 60 seconds on
// the recipient's device.
DeviceProcessEvents
| where Timestamp > ago(LookbackDays)
| where InitiatingProcessFileName in~ ("chrome.exe","msedge.exe","firefox.exe",
                                         "outlook.exe","brave.exe","arc.exe")
| where FileName in~ ("powershell.exe","pwsh.exe","cmd.exe","mshta.exe",
                        "rundll32.exe","regsvr32.exe","wscript.exe","cscript.exe",
                        "bitsadmin.exe","certutil.exe","curl.exe","wget.exe")
| join kind=inner SuspectClicks on $left.AccountName == $right.AccountUpn
| where Timestamp between (ClickTime .. ClickTime + 60s)
| project ClickTime, ProcessTime = Timestamp,
          DelaySec = datetime_diff('second', Timestamp, ClickTime),
          DeviceName, AccountName, RecipientEmailAddress, SenderFromAddress,
          Subject, Url, UrlDomain, ActionType,
          FileName, ProcessCommandLine, InitiatingProcessFileName
| order by ClickTime desc
```

### Email attachment opened from external sender

`UC_PHISH_ATTACH` · phase: **delivery** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count
    from datamodel=Email.All_Email
    where All_Email.file_name!="-"
    by All_Email.src_user, All_Email.recipient, All_Email.file_name, All_Email.subject
| rename All_Email.recipient as user
| join type=inner user
    [| tstats `summariesonly` count
        from datamodel=Endpoint.Processes
        where Processes.parent_process_name IN ("OUTLOOK.EXE","winword.exe","excel.exe","powerpnt.exe")
          AND Processes.process_name IN ("cmd.exe","powershell.exe","wscript.exe","cscript.exe","mshta.exe","rundll32.exe","regsvr32.exe")
        by Processes.dest, Processes.user, Processes.parent_process_name, Processes.process_name, Processes.process
     | rename Processes.user as user]
```

**Defender KQL:**
```kql
let LookbackDays = 7d;
let MalAttachments = EmailAttachmentInfo
    | where Timestamp > ago(LookbackDays)
    | where AccountName !endswith "$"
    | project NetworkMessageId, RecipientEmailAddress,
              AttachmentFileName = FileName, AttachmentSHA256 = SHA256;
DeviceProcessEvents
| where Timestamp > ago(LookbackDays)
| where InitiatingProcessFileName in~ ("OUTLOOK.EXE","winword.exe","excel.exe","powerpnt.exe")
| where FileName in~ ("cmd.exe","powershell.exe","wscript.exe","cscript.exe",
                      "mshta.exe","rundll32.exe","regsvr32.exe")
| join kind=inner MalAttachments on $left.AccountUpn == $right.RecipientEmailAddress
| project Timestamp, DeviceName, AccountName, FileName, ProcessCommandLine,
          InitiatingProcessFileName, AttachmentFileName, AttachmentSHA256
```

### Office app spawning script/LOLBin child process

`UC_OFFICE_CHILD` · phase: **exploit** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where Processes.parent_process_name IN ("winword.exe","excel.exe","powerpnt.exe","outlook.exe","onenote.exe","mspub.exe","visio.exe")
      AND Processes.process_name IN ("cmd.exe","powershell.exe","pwsh.exe","wscript.exe","cscript.exe","mshta.exe","rundll32.exe","regsvr32.exe","wmic.exe","bitsadmin.exe","certutil.exe")
    by Processes.dest, Processes.user, Processes.parent_process_name, Processes.process_name, Processes.process
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where InitiatingProcessFileName in~ ("winword.exe","excel.exe","powerpnt.exe","outlook.exe","onenote.exe","mspub.exe","visio.exe")
| where FileName in~ ("cmd.exe","powershell.exe","pwsh.exe","wscript.exe","cscript.exe","mshta.exe","rundll32.exe","regsvr32.exe","wmic.exe","bitsadmin.exe","certutil.exe")
| project Timestamp, DeviceName, AccountName, InitiatingProcessFileName, FileName, ProcessCommandLine
```

### Microsoft Teams external-tenant chat from unverified IT-helpdesk impersonator

`UC_TEAMS_VISHING` · phase: **delivery** · confidence: **High**

**Splunk SPL (CIM):**
```spl
`o365_management_activity`
  Workload=MicrosoftTeams Operation=MessageSent
  ExternalParticipants=*
| where match(SenderDisplayName, "(?i)(help.?desk|it.?support|service.?desk|tech.?support|admin)")
| stats count, earliest(_time) as firstTime, latest(_time) as lastTime
    by SenderUpn, SenderDisplayName, RecipientUpn, ChatId
```

**Defender KQL:**
```kql
CloudAppEvents
| where Timestamp > ago(7d)
| where Application == "Microsoft Teams"
| where ActionType == "MessageSent"
| where RawEventData has "ExternalParticipants"
| extend SenderDisplayName = tostring(parse_json(RawEventData).SenderDisplayName)
| where SenderDisplayName matches regex @"(?i)(help.?desk|it.?support|service.?desk|tech.?support|admin)"
| project Timestamp, AccountDisplayName, IPAddress, ActivityType, SenderDisplayName, RawEventData
```

### RMM tool installed by non-IT user — remote-access utility for hands-on-keyboard

`UC_RMM_TOOLS` · phase: **install** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where Processes.process_name IN ("AnyDesk.exe","TeamViewer.exe","TeamViewer_Service.exe",
        "ScreenConnect.ClientService.exe","ConnectWiseControl.ClientService.exe",
        "atera_agent.exe","SplashtopStreamer.exe","RustDesk.exe","NinjaOne.exe","kaseya*.exe")
    by Processes.dest, Processes.user, Processes.process_name, Processes.process, Processes.parent_process_name
| `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where FileName in~ ("AnyDesk.exe","TeamViewer.exe","TeamViewer_Service.exe",
        "ScreenConnect.ClientService.exe","ConnectWiseControl.ClientService.exe",
        "atera_agent.exe","SplashtopStreamer.exe","RustDesk.exe","NinjaOne.exe")
   or FileName matches regex @"(?i)kaseya.*\.exe"
| project Timestamp, DeviceName, AccountName, FileName, ProcessCommandLine
```

### Trusted vendor binary / installer launching unusual children

`UC_SUPPLY_CHAIN` · phase: **exploit** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where Processes.parent_process_name IN ("setup.exe","installer.exe","update.exe")
      AND Processes.process_name IN ("powershell.exe","cmd.exe","rundll32.exe","regsvr32.exe","mshta.exe","wscript.exe","cscript.exe","wmic.exe","bitsadmin.exe")
    by Processes.dest, Processes.user, Processes.parent_process_name, Processes.process_name, Processes.process
| `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where InitiatingProcessFileName in~ ("setup.exe","installer.exe","update.exe")
| where FileName in~ ("powershell.exe","cmd.exe","rundll32.exe","regsvr32.exe","mshta.exe","wscript.exe","cscript.exe","wmic.exe","bitsadmin.exe")
| project Timestamp, DeviceName, AccountName, InitiatingProcessFileName, FileName, ProcessCommandLine
```

### Article-specific behavioural hunt — Tracing Digital Intent: New MacOS Tahoe 26 Artifact Discovered

`UC_15_6` · phase: **exploit** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — Tracing Digital Intent: New MacOS Tahoe 26 Artifact Discovered ```
| tstats `summariesonly` count earliest(_time) AS firstTime latest(_time) AS lastTime
    from datamodel=Endpoint.Processes
    where (Processes.process_name IN ("ccl_segb_cli.py"))
    by Processes.dest, Processes.user, Processes.process_name,
       Processes.process, Processes.parent_process_name, Processes.process_path
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| append [
| tstats `summariesonly` count
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("created","modified")
      AND (Filesystem.file_path="*/Library/Biome/streams/restricted/App.MenuItem/local*" OR Filesystem.file_name IN ("ccl_segb_cli.py"))
    by Filesystem.dest, Filesystem.user, Filesystem.process_name,
       Filesystem.file_path, Filesystem.file_name
| `drop_dm_object_name(Filesystem)`
]
```

**Defender KQL:**
```kql
// Article-specific bespoke detection — Tracing Digital Intent: New MacOS Tahoe 26 Artifact Discovered
// Hunts the actual binaries / paths / commandline fragments named
// in the article instead of a generic technique-class template.
DeviceProcessEvents
| where Timestamp > ago(30d)
| where (FileName in~ ("ccl_segb_cli.py"))
| project Timestamp, DeviceName, AccountName, FileName,
          FolderPath, ProcessCommandLine,
          InitiatingProcessFileName, InitiatingProcessCommandLine
| order by Timestamp desc

// File-creation events for the named binaries / paths
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated","FileModified")
| where (FolderPath has_any ("/Library/Biome/streams/restricted/App.MenuItem/local") or FileName in~ ("ccl_segb_cli.py"))
| project Timestamp, DeviceName, AccountName, FolderPath,
          FileName, ActionType, InitiatingProcessFileName,
          InitiatingProcessCommandLine
| order by Timestamp desc
```


## Why this matters

Severity classified as **CRIT** based on: 9 use case(s) fired, 16 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.