# [HIGH] Checkmarx KICS GitHub Action Compromised: Malware Injected in All Git Tags

**Source:** StepSecurity
**Published:** 2026-03-26
**Article:** https://www.stepsecurity.io/blog/checkmarx-kics-github-action-compromised-malware-injected-in-all-git-tags

## Threat Profile

Back to Blog Threat Intel Checkmarx KICS GitHub Action Compromised: Malware Injected in All Git Tags All release tags in the Checkmarx/kics-github-action repository have been compromised with an infostealer payload. If you are using this Action pinned to any version tag, treat your CI/CD secrets as compromised and rotate immediately. Ashish Kurmi View LinkedIn March 23, 2026
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Summary O…

## Indicators of Compromise (high-fidelity only)

- **Domain (defanged):** `checkmarx.zone`

## MITRE ATT&CK Techniques

- **T1539** — Steal Web Session Cookie
- **T1555.003** — Credentials from Web Browsers
- **T1195.002** — Compromise Software Supply Chain
- **T1071** — Application Layer Protocol
- **T1204.002** — User Execution: Malicious File
- **T1071.001** — Application Layer Protocol: Web Protocols
- **T1567.002** — Exfiltration to Cloud Storage
- **T1543.002** — Create or Modify System Process: Systemd Service
- **T1059.006** — Command and Scripting Interpreter: Python
- **T1560.001** — Archive Collected Data: Archive via Utility
- **T1552.001** — Unsecured Credentials: Credentials In Files

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### TeamPCP supply-chain C2 — outbound to checkmarx[.]zone / 83.142.209.11

`UC_428_4` · phase: **c2** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=t count min(_time) as firstTime max(_time) as lastTime values(All_Traffic.dest_port) as dest_port values(All_Traffic.app) as app values(All_Traffic.process_name) as process_name from datamodel=Network_Traffic.All_Traffic where (All_Traffic.dest_ip="83.142.209.11" OR All_Traffic.dest="*checkmarx.zone*") by All_Traffic.src All_Traffic.dest All_Traffic.dest_ip All_Traffic.user | `drop_dm_object_name(All_Traffic)` | append [ | tstats summariesonly=t count min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Resolution.DNS where DNS.query="*checkmarx.zone" by DNS.src DNS.query | `drop_dm_object_name(DNS)` | rename query as dest] | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
let _badDomain = "checkmarx.zone";
let _badIP = "83.142.209.11";
union isfuzzy=true
  ( DeviceNetworkEvents
    | where Timestamp > ago(7d)
    | where RemoteUrl has _badDomain or RemoteIP == _badIP
    | project Timestamp, DeviceName, ActionType, RemoteIP, RemotePort, RemoteUrl,
              InitiatingProcessFileName, InitiatingProcessCommandLine,
              InitiatingProcessAccountName, InitiatingProcessFolderPath ),
  ( DeviceEvents
    | where Timestamp > ago(7d)
    | where ActionType == "DnsQueryResponse"
    | extend Q = tostring(parse_json(AdditionalFields).QueryName)
    | where Q has _badDomain
    | project Timestamp, DeviceName, ActionType, RemoteUrl = Q,
              InitiatingProcessFileName, InitiatingProcessCommandLine,
              InitiatingProcessAccountName, InitiatingProcessFolderPath )
| order by Timestamp desc
```

### TeamPCP systemd backdoor — sysmon.py / sysmon.service persistence on CI runner

`UC_428_5` · phase: **install** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=t count min(_time) as firstTime max(_time) as lastTime values(Filesystem.process_name) as process_name values(Filesystem.action) as action from datamodel=Endpoint.Filesystem where (Filesystem.file_path="*/.config/sysmon/sysmon.py" OR Filesystem.file_path="*/.config/systemd/user/sysmon.service") by Filesystem.dest Filesystem.user Filesystem.file_name Filesystem.file_path | `drop_dm_object_name(Filesystem)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(7d)
| where ActionType in ("FileCreated", "FileModified", "FileRenamed")
| where ( FolderPath has "/.config/sysmon" and FileName =~ "sysmon.py" )
    or ( FolderPath has "/.config/systemd/user" and FileName =~ "sysmon.service" )
| project Timestamp, DeviceName, ActionType, FileName, FolderPath, SHA256, FileSize,
          InitiatingProcessAccountName, InitiatingProcessFileName,
          InitiatingProcessCommandLine, InitiatingProcessFolderPath,
          InitiatingProcessParentFileName
| order by Timestamp desc
```

### TeamPCP exfiltration archive — tpcp.tar.gz file creation on host

`UC_428_6` · phase: **actions** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=t count min(_time) as firstTime max(_time) as lastTime values(Filesystem.process_name) as process_name values(Filesystem.action) as action from datamodel=Endpoint.Filesystem where Filesystem.file_name="tpcp.tar.gz" by Filesystem.dest Filesystem.user Filesystem.file_name Filesystem.file_path | `drop_dm_object_name(Filesystem)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated", "FileModified", "FileRenamed")
| where FileName =~ "tpcp.tar.gz"
| project Timestamp, DeviceName, ActionType, FileName, FolderPath, SHA256, FileSize,
          InitiatingProcessAccountName, InitiatingProcessFileName,
          InitiatingProcessCommandLine, InitiatingProcessFolderPath,
          InitiatingProcessParentFileName, InitiatingProcessParentCreationTime
| order by Timestamp desc
```

### 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 — Checkmarx KICS GitHub Action Compromised: Malware Injected in All Git Tags

`UC_428_3` · phase: **exploit** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — Checkmarx KICS GitHub Action Compromised: Malware Injected in All Git Tags ```
| tstats `summariesonly` count earliest(_time) AS firstTime latest(_time) AS lastTime
    from datamodel=Endpoint.Processes
    where (Processes.process_name IN ("setup.sh"))
    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_name IN ("setup.sh"))
    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 — Checkmarx KICS GitHub Action Compromised: Malware Injected in All Git Tags
// 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~ ("setup.sh"))
| 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 (FileName in~ ("setup.sh"))
| 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): `checkmarx.zone`


## Why this matters

Severity classified as **HIGH** based on: IOCs present, 7 use case(s) fired, 11 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.