# [HIGH] Microsoft links Mastra AI supply chain attack to North Korean hackers

**Source:** BleepingComputer
**Published:** 2026-06-20
**Article:** https://www.bleepingcomputer.com/news/security/microsoft-links-mastra-ai-supply-chain-attack-to-north-korean-hackers/

## Threat Profile

Microsoft links Mastra AI supply chain attack to North Korean hackers 
By Lawrence Abrams 
June 20, 2026
10:09 AM
0 
Microsoft has attributed a recent Mastra AI supply chain attack that compromised more than 140 npm packages to the North Korean hacking group Sapphire Sleet, also known as BlueNoroff.
This attribution comes after Microsoft first disclosed earlier this week that attackers hijacked an npm maintainer account and used it to publish malicious package updates.
"Microsoft assesses with h…

## Indicators of Compromise (high-fidelity only)

- **IPv4 (defanged):** `23.254.164.92`
- **IPv4 (defanged):** `23.254.164.123`
- **Domain (defanged):** `teams.onweblive.org`
- **Domain (defanged):** `maskasd.com`
- **SHA256:** `b122a9873bedf145ae2a7fd024b5f309007dbb025149f4dc4ac3f7e4f32a36a4`
- **SHA256:** `ae70dd4f6bc0d1c8c2848e4e6b51934626c4818dcb5af99d080ddbd7dc337185`
- **SHA256:** `4a8860240e4231c3a74c81949be655a28e096a7d72f38fbe84e5b37636b98417`
- **SHA256:** `b73de25c053c3225a077738a1fcbd9ca6966d7b3cd6f5494a30f0aa0eae55c7e`
- **SHA256:** `221c45a790dec2a296af57969e1165a16f8f49733aeab64c0bbd768d9943badf`
- **SHA256:** `50eae63d3e24be9ca8803f4b5a0408aef97ee3fab7af018d8c2dde7c359edd65`
- **SHA256:** `1d1bf5e8c1539d2f05b1429235b8f4990f87036774be95157b315a7803dd5526`

## MITRE ATT&CK Techniques

- **T1071.001** — Web Protocols
- **T1071.004** — DNS
- **T1071** — Application Layer Protocol
- **T1176** — Browser Extensions
- **T1539** — Steal Web Session Cookie
- **T1555.003** — Credentials from Web Browsers
- **T1005** — Data from Local System
- **T1059.001** — PowerShell
- **T1027** — Obfuscated Files or Information
- **T1195.002** — Compromise Software Supply Chain
- **T1059.007** — JavaScript
- **T1564.003** — Hidden Window
- **T1105** — Ingress Tool Transfer
- **T1562.001** — Disable or Modify Tools

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Sapphire Sleet 'easy-day-js' typosquat dependency landed in node_modules (@mastra supply chain)

`UC_2_8` · phase: **install** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where (Filesystem.file_path="*\\node_modules\\easy-day-js\\*" OR Filesystem.file_path="*/node_modules/easy-day-js/*") by Filesystem.dest Filesystem.user Filesystem.file_path Filesystem.file_name Filesystem.process_name | `drop_dm_object_name(Filesystem)` | convert ctime(firstTime) ctime(lastTime) | sort - lastTime
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(30d)
| where FolderPath has @"\node_modules\easy-day-js" or FolderPath has "/node_modules/easy-day-js"
| where InitiatingProcessAccountName !endswith "$"
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, InitiatingProcessCommandLine, FolderPath, FileName, SHA256
| order by Timestamp desc
```

### npm postinstall dropper: node.exe spawning shell/script host or detached child (Mastra easy-day-js)

`UC_2_9` · phase: **exploit** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name="node.exe" AND (Processes.process_name IN ("powershell.exe","pwsh.exe","cmd.exe","wscript.exe","cscript.exe","mshta.exe","curl.exe","node.exe") OR Processes.process="*NODE_TLS_REJECT_UNAUTHORIZED*") by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.process | `drop_dm_object_name(Processes)` | convert ctime(firstTime) ctime(lastTime) | sort - lastTime
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(30d)
| where InitiatingProcessFileName =~ "node.exe"
| where (FileName in~ ("powershell.exe","pwsh.exe","cmd.exe","wscript.exe","cscript.exe","mshta.exe","curl.exe","node.exe"))
    or ProcessCommandLine has "NODE_TLS_REJECT_UNAUTHORIZED"
    or InitiatingProcessCommandLine has "NODE_TLS_REJECT_UNAUTHORIZED"
| where AccountName !endswith "$"
| project Timestamp, DeviceName, AccountName, InitiatingProcessFileName, InitiatingProcessCommandLine, FileName, ProcessCommandLine, FolderPath, SHA256
| order by Timestamp desc
```

### C2 / second-stage fetch to Sapphire Sleet (BlueNoroff) Mastra infrastructure

`UC_2_10` · phase: **c2** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Traffic.All_Traffic where (All_Traffic.dest_ip IN ("23.254.164.92","23.254.164.123") OR All_Traffic.dest IN ("teams.onweblive.org","maskasd.com")) by All_Traffic.src All_Traffic.dest All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.app | `drop_dm_object_name(All_Traffic)` | convert ctime(firstTime) ctime(lastTime) | sort - lastTime
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where RemoteIP in ("23.254.164.92","23.254.164.123")
    or RemoteUrl has_any ("teams.onweblive.org","maskasd.com")
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, InitiatingProcessCommandLine, RemoteIP, RemoteUrl, RemotePort, Protocol
| order by Timestamp desc
```

### Cross-platform stealer: non-browser process accessing browser credential & crypto-wallet extension stores

`UC_2_11` · phase: **actions** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where (Filesystem.file_path="*\\Local Extension Settings\\*" OR Filesystem.file_path="*\\Login Data*" OR Filesystem.file_path="*\\Web Data*" OR Filesystem.file_path="*\\Local Storage\\leveldb*") AND NOT Filesystem.process_name IN ("chrome.exe","msedge.exe","brave.exe","firefox.exe","opera.exe","msedgewebview2.exe") by Filesystem.dest Filesystem.user Filesystem.process_name Filesystem.file_path | `drop_dm_object_name(Filesystem)` | convert ctime(firstTime) ctime(lastTime) | sort - lastTime
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(30d)
| where FolderPath has_any (@"\Local Extension Settings\", @"\Extension State\", @"\Local Storage\leveldb", @"\Login Data", @"\Web Data")
| where InitiatingProcessFileName !in~ ("chrome.exe","msedge.exe","brave.exe","firefox.exe","opera.exe","chrome_proxy.exe","msedgewebview2.exe")
| where InitiatingProcessAccountName !endswith "$"
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, InitiatingProcessFolderPath, InitiatingProcessCommandLine, FolderPath, FileName, ActionType
| order by Timestamp desc
```

### Sapphire Sleet follow-on: Microsoft Defender exclusion added (Add/Set-MpPreference)

`UC_2_12` · phase: **install** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process="*Add-MpPreference*" OR Processes.process="*Set-MpPreference*") AND (Processes.process="*Exclusion*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process | `drop_dm_object_name(Processes)` | convert ctime(firstTime) ctime(lastTime) | sort - lastTime
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(30d)
| where ProcessCommandLine has_any ("Add-MpPreference","Set-MpPreference")
| where ProcessCommandLine has_any ("ExclusionPath","ExclusionProcess","ExclusionExtension")
| where AccountName !endswith "$"
| project Timestamp, DeviceName, AccountName, InitiatingProcessFileName, InitiatingProcessCommandLine, FileName, ProcessCommandLine, SHA256
| order by Timestamp desc
```

### Beaconing — periodic outbound to small set of destinations

`UC_BEACONING` · phase: **c2** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count, values(All_Traffic.dest_port) AS ports
    from datamodel=Network_Traffic.All_Traffic
    where All_Traffic.action="allowed" AND All_Traffic.dest_category!="internal"
    by _time span=10s, All_Traffic.src, All_Traffic.dest
| `drop_dm_object_name(All_Traffic)`
| streamstats current=f last(_time) AS prev_time by src, dest
| eval delta = _time - prev_time
| stats avg(delta) AS avg_delta stdev(delta) AS sd_delta count by src, dest
| where count > 30 AND sd_delta < 5 AND avg_delta>=30 AND avg_delta<=600
| sort - count
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(1d)
| where RemoteIPType == "Public" and ActionType == "ConnectionSuccess"
| project DeviceName, RemoteIP, RemotePort, Timestamp
| sort by DeviceName asc, RemoteIP asc, RemotePort asc, Timestamp asc
| extend prev_dev = prev(DeviceName, 1), prev_ip = prev(RemoteIP, 1),
         prev_port = prev(RemotePort, 1), prev_ts = prev(Timestamp, 1)
| where DeviceName == prev_dev and RemoteIP == prev_ip and RemotePort == prev_port
| extend delta_sec = datetime_diff('second', Timestamp, prev_ts)
| summarize conn_count = count(), avg_delta = avg(delta_sec), stdev_delta = stdev(delta_sec)
    by DeviceName, RemoteIP, RemotePort
| where conn_count > 30 and avg_delta between (30.0 .. 600.0) and stdev_delta < 5.0
| order by conn_count desc
```

### Suspicious browser extension installation

`UC_BROWSER_EXT` · phase: **install** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Registry
    where (Registry.registry_path="*\Software\Google\Chrome\Extensions\*"
        OR Registry.registry_path="*\Software\Microsoft\Edge\Extensions\*"
        OR Registry.registry_path="*\Software\Mozilla\Firefox\Extensions\*")
    by Registry.dest, Registry.registry_path, Registry.registry_value_data, Registry.registry_value_name, Registry.user
| `drop_dm_object_name(Registry)`
```

**Defender KQL:**
```kql
DeviceRegistryEvents
| where Timestamp > ago(7d)
| where InitiatingProcessAccountName !endswith "$"
| where RegistryKey has_any ("\Software\Google\Chrome\Extensions\","\Software\Microsoft\Edge\Extensions\","\Software\Mozilla\Firefox\Extensions\")
| project Timestamp, DeviceName, RegistryKey, RegistryValueName, RegistryValueData,
          InitiatingProcessFileName, InitiatingProcessAccountName
```

### Infostealer — non-browser process accessing browser cookie/login DBs

`UC_BROWSER_STEALER` · phase: **actions** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Filesystem
    where (Filesystem.file_path="*\Google\Chrome\User Data\*\Login Data*"
        OR Filesystem.file_path="*\Google\Chrome\User Data\*\Cookies*"
        OR Filesystem.file_path="*\Microsoft\Edge\User Data\*\Login Data*"
        OR Filesystem.file_path="*\Mozilla\Firefox\Profiles\*\logins.json*"
        OR Filesystem.file_path="*\Mozilla\Firefox\Profiles\*\cookies.sqlite*")
      AND NOT Filesystem.process_name IN ("chrome.exe","msedge.exe","firefox.exe","brave.exe","opera.exe")
    by Filesystem.dest, Filesystem.process_name, Filesystem.file_path, Filesystem.user
| `drop_dm_object_name(Filesystem)`
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(7d)
| where InitiatingProcessAccountName !endswith "$"
| where FolderPath has_any (@"\Google\Chrome\User Data\", @"\Microsoft\Edge\User Data\", @"\Mozilla\Firefox\Profiles\")
| where FileName in~ ("Login Data","Cookies","logins.json","cookies.sqlite")
| where InitiatingProcessFileName !in~ ("chrome.exe","msedge.exe","firefox.exe","brave.exe","opera.exe")
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, FolderPath, FileName, ActionType
```

### Crypto-wallet file/keystore access by non-wallet process

`UC_CRYPTO_WALLET` · phase: **actions** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Filesystem
    where (Filesystem.file_path="*\Ethereum\keystore\*"
        OR Filesystem.file_path="*\Bitcoin\wallet.dat"
        OR Filesystem.file_path="*\Exodus\exodus.wallet*"
        OR Filesystem.file_path="*\Electrum\wallets\*"
        OR Filesystem.file_path="*\MetaMask\*"
        OR Filesystem.file_path="*\Phantom\*"
        OR Filesystem.file_path="*\Atomic\Local Storage\*")
      AND NOT Filesystem.process_name IN ("MetaMask.exe","Exodus.exe","Atomic.exe","electrum.exe","Bitcoin.exe","Phantom.exe")
    by Filesystem.dest, Filesystem.process_name, Filesystem.file_path, Filesystem.user
| `drop_dm_object_name(Filesystem)`
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(7d)
| where InitiatingProcessAccountName !endswith "$"
| where FolderPath has_any (@"\Ethereum\keystore\", @"\Bitcoin\", @"\Exodus\", @"\Electrum\wallets\", @"\MetaMask\", @"\Phantom\", @"\Atomic\Local Storage\")
| where InitiatingProcessFileName !in~ ("MetaMask.exe","Exodus.exe","Atomic.exe","electrum.exe","Bitcoin.exe","Phantom.exe")
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, FolderPath, FileName, ActionType
```

### PowerShell encoded / obfuscated command

`UC_PS_OBFUSCATED` · 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.process_name IN ("powershell.exe","pwsh.exe")
      AND (Processes.process="*-enc *" OR Processes.process="*EncodedCommand*"
        OR Processes.process="*FromBase64String*" OR Processes.process="*-nop*"
        OR Processes.process="*-w hidden*" OR Processes.process="*Invoke-Expression*"
        OR Processes.process="*IEX(*" OR Processes.process="*DownloadString*"
        OR Processes.process="*Net.WebClient*")
    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~ ("powershell.exe","pwsh.exe")
| where ProcessCommandLine matches regex @"(?i)(-enc|encodedcommand|frombase64string|-nop|-w\s+hidden|invoke-expression|iex\s*\(|downloadstring|net\.webclient)"
| project Timestamp, DeviceName, AccountName, ProcessCommandLine,
          InitiatingProcessFileName, InitiatingProcessCommandLine
```

### 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
```

### IOC-driven hunts (use shared templates)

These are standard IOC-substitution hunts — the canonical SPL and KQL live once in [`_TEMPLATES.md`](../_TEMPLATES.md), so we don't repeat the same boilerplate on every CVE / hash / network-IOC briefing.

- **Network connections to article IPs / domains** ([template](../_TEMPLATES.md#network-ioc)) — phase: **c2**, confidence: **High**
  - IP / domain IOC(s): `23.254.164.92`, `23.254.164.123`, `teams.onweblive.org`, `maskasd.com`

- **File hash IOCs — endpoint file/process match** ([template](../_TEMPLATES.md#hash-ioc)) — phase: **install**, confidence: **High**
  - file hash IOC(s): `b122a9873bedf145ae2a7fd024b5f309007dbb025149f4dc4ac3f7e4f32a36a4`, `ae70dd4f6bc0d1c8c2848e4e6b51934626c4818dcb5af99d080ddbd7dc337185`, `4a8860240e4231c3a74c81949be655a28e096a7d72f38fbe84e5b37636b98417`, `b73de25c053c3225a077738a1fcbd9ca6966d7b3cd6f5494a30f0aa0eae55c7e`, `221c45a790dec2a296af57969e1165a16f8f49733aeab64c0bbd768d9943badf`, `50eae63d3e24be9ca8803f4b5a0408aef97ee3fab7af018d8c2dde7c359edd65`, `1d1bf5e8c1539d2f05b1429235b8f4990f87036774be95157b315a7803dd5526`


## Why this matters

Severity classified as **HIGH** based on: IOCs present, 13 use case(s) fired, 14 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.