# [HIGH] 15 Malicious JetBrains Plugins Stole AI API Keys from 70,000 Developers

**Source:** StepSecurity
**Published:** 2026-06-20
**Article:** https://www.stepsecurity.io/blog/jetbrains-malicious-plugins-ai-api-key-theft

## Threat Profile

Back to Blog Threat Intel 15 Malicious JetBrains Plugins Stole AI API Keys from 70,000 Developers A coordinated 8-month supply chain attack planted credential-stealing code inside fake AI coding assistants on the JetBrains Marketplace, quietly exfiltrating OpenAI, DeepSeek, and SiliconFlow API keys to an attacker-controlled server in Beijing -- which our investigation found still operational today. Ashish Kurmi View LinkedIn June 18, 2026
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## Indicators of Compromise (high-fidelity only)

- **IPv4 (defanged):** `39.107.60.51`

## 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
- **T1195.002** — Compromise Software Supply Chain
- **T1204.002** — User Execution: Malicious File
- **T1071.001** — Application Layer Protocol: Web Protocols
- **T1041** — Exfiltration Over C2 Channel

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### JetBrains IDE process beaconing to malicious plugin C2 39.107.60.51

`UC_0_6` · phase: **c2** · confidence: **High** · 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="39.107.60.51" by All_Traffic.src All_Traffic.dest All_Traffic.dest_port All_Traffic.app All_Traffic.transport
| `drop_dm_object_name(All_Traffic)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| sort - lastTime
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where RemoteIP == "39.107.60.51"
| summarize FirstSeen=min(Timestamp), LastSeen=max(Timestamp), Connections=count(), Ports=make_set(RemotePort), Urls=make_set(RemoteUrl) by DeviceName, InitiatingProcessFileName, InitiatingProcessFolderPath, InitiatingProcessAccountName
| order by LastSeen desc
```

### Install of known-malicious JetBrains Marketplace plugin (15 trojanized plugin IDs)

`UC_0_7` · phase: **delivery** · 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="*org.sm.yms.toolkit*" OR Filesystem.file_path="*com.json.simple.kit*" OR Filesystem.file_path="*org.bug.find.tools*" OR Filesystem.file_path="*org.translate.ai.simple*" OR Filesystem.file_path="*com.yy.test.ai.simple*" OR Filesystem.file_path="*com.dev.ai.toolkit*" OR Filesystem.file_path="*com.json.view.simple*" OR Filesystem.file_path="*com.my.git.ai.kit*" OR Filesystem.file_path="*org.check.ai.ds*" OR Filesystem.file_path="*com.review.tool.code*" OR Filesystem.file_path="*org.code.assist.dev.tool*" OR Filesystem.file_path="*com.coder.ai.dpt*" OR Filesystem.file_path="*com.my.code.tools*" OR Filesystem.file_path="*ord.cp.code.ai.kit*") by Filesystem.dest Filesystem.file_name Filesystem.file_path Filesystem.user
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
let MaliciousPluginIds = dynamic(["org.sm.yms.toolkit","com.json.simple.kit","org.bug.find.tools","org.translate.ai.simple","com.yy.test.ai.simple","com.dev.ai.toolkit","com.json.view.simple","com.my.git.ai.kit","org.check.ai.ds","com.review.tool.code","org.code.assist.dev.tool","com.coder.ai.dpt","com.my.code.tools","ord.cp.code.ai.kit"]);
DeviceFileEvents
| where Timestamp > ago(90d)
| where FolderPath has_any (MaliciousPluginIds) or FileName has_any (MaliciousPluginIds)
| project Timestamp, DeviceName, InitiatingProcessAccountName, ActionType, FileName, FolderPath, SHA256, InitiatingProcessFileName, InitiatingProcessCommandLine
| order by Timestamp desc
```

### JetBrains IDE JVM plaintext HTTP POST to AI-key stealer endpoint /api/software/

`UC_0_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 from datamodel=Web.Web where (Web.dest="39.107.60.51" OR Web.url="*/api/software/*") AND Web.http_method="POST" by Web.src Web.dest Web.url Web.http_method Web.http_user_agent Web.dest_port
| `drop_dm_object_name(Web)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where InitiatingProcessFileName in~ ("idea64.exe","idea.exe","pycharm64.exe","pycharm.exe","webstorm64.exe","phpstorm64.exe","goland64.exe","rider64.exe","clion64.exe","rubymine64.exe","datagrip64.exe","java.exe","javaw.exe")
| where RemotePort == 80 and RemoteIPType == "Public"
| where RemoteIP == "39.107.60.51" or RemoteUrl has "/api/software/"
| project Timestamp, DeviceName, InitiatingProcessAccountName, InitiatingProcessFileName, InitiatingProcessFolderPath, RemoteIP, RemotePort, RemoteUrl
| 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
```

### 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 — 15 Malicious JetBrains Plugins Stole AI API Keys from 70,000 Developers

`UC_0_5` · phase: **install** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — 15 Malicious JetBrains Plugins Stole AI API Keys from 70,000 Developers ```
| tstats `summariesonly` count
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("created","modified")
      AND (Filesystem.file_path="*/Library/Application*")
    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 — 15 Malicious JetBrains Plugins Stole AI API Keys from 70,000 Developers
// Hunts the actual binaries / paths / commandline fragments named
// in the article instead of a generic technique-class template.

// File-creation events for the named binaries / paths
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated","FileModified")
| where (FolderPath has_any ("/Library/Application"))
| project Timestamp, DeviceName, AccountName, FolderPath,
          FileName, ActionType, InitiatingProcessFileName,
          InitiatingProcessCommandLine
| order by Timestamp desc
```

### 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): `39.107.60.51`


## Why this matters

Severity classified as **HIGH** based on: IOCs present, 9 use case(s) fired, 10 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.