S1236: CLAIMLOADER
CLAIMLOADER is a malware variant that frequently accompanies legitimate executables that are used for DLL side-loading known to be leveraged by Mustang Panda and was first observed utilized in 2021.[1][2]
Security context for executives and security teams
S1236: CLAIMLOADER describes [CLAIMLOADER](https://attack.mitre.org/software/S1236) is a malware variant that frequently accompanies legitimate executables that are used for DLL side-loading known to be leveraged by [Mustang Panda](https://attack.mitre.org/groups/G0129) and was first observed utilized in 2021.(Citation: IBM MUSTANG PANDA PUBLOAD CLAIMLOADER JUNE 2025)(Citation: 2025_IBM_PUBLOAD_TONESHELL_HIUPAN_CLAIMLOADER_MUSTANG PANDA)
Executive priority
S1236: CLAIMLOADER is an official MITRE ATT&CK software. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.
Technical view
Security teams should validate S1236: CLAIMLOADER by reviewing the official ATT&CK relationships, mapped tactics (the mapped ATT&CK tactic context), supported platforms (Windows), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether S1236: CLAIMLOADER appears in your detection coverage and tabletop scenarios.
- Use the object to align executive risk language with SOC, incident response, and detection engineering work.
- Do not treat ATT&CK relationship context as attribution without corroborating evidence.
Mitigation priorities
- Map the object to existing controls and identify missing telemetry or response ownership.
- Prioritize mitigations that reduce exposure on the listed platforms and tactics.
- Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits
Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.
This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
CLAIMLOADER
CLAIMLOADER is a malware variant that frequently accompanies legitimate executables that are used for DLL side-loading known to be leveraged by Mustang Panda and was first observed utilized in 2021.[1][2]
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Techniques used
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| Enterprise | T1559.001 | Component Object ModelSub-technique | CLAIMLOADER has leveraged Component Object Model (COM) objects to create a scheduled task using `ITaskService` interface.[2] |
| Enterprise | T1106 | Native API | CLAIMLOADER has used various Windows API calls during execution, when establishing persistence and defense evasion.[1][2] CLAIMLOADER has also leveraged the legitimate API functions to run its shellcode through the callback function, including `GetDC()` and `EnumFontsW()`.[1] CLAIMLOADER established persistence by utilizing the API `SHSetValue()`.[1] CLAIMLOADER has utilized APIs with callback functions such as `EnumpropsExW`, `EnumSystemLanguageGroupsA`, and `EnumCalendarInfoExW`.[2] |
| Enterprise | T1547.001 | Registry Run Keys / Startup FolderSub-technique | CLAIMLOADER has added Registry Run keys to achieve persistence using `HKCU\Software\Microsoft\Windows\CurrentVersion\Run`.[1][2] |
| Enterprise | T1574.001 | DLLSub-technique | CLAIMLOADER has used a legitimately signed executable to execute a malicious payload within a DLL file.[1] |
| Enterprise | T1564.001 | Hidden Files and DirectoriesSub-technique | CLAIMLOADER has modified file attributes to remain hidden to a standard user.[2] |
| Enterprise | T1036.005 | Match Legitimate Resource Name or LocationSub-technique | CLAIMLOADER has imitated legitimate software directories through the creation and storage of the EXE and DLL in `C:\ProgramData\` and the use of legitimate looking names of software.[2] |
| Enterprise | T1480.002 | Mutual ExclusionSub-technique | CLAIMLOADER has created hardcoded mutex to ensure only a single instance of the malware is running.[1][2] |
| Enterprise | T1204.002 | Malicious FileSub-technique | CLAIMLOADER has used tailored decoy documents as part of the installation routine to entice users to open attachments.[2] |
| Enterprise | T1053.005 | Scheduled TaskSub-technique | CLAIMLOADER has created scheduled tasks that execute the loader every five(5) minutes using `schtasks /F /Create /TN \"\" /SC minute /MO 5 /TR \"C:\\ProgramData\\ \`.[2] |
| Enterprise | T1140 | Deobfuscate/Decode Files or Information | CLAIMLOADER has decoded its payload prior to execution.[1][2] |
| Enterprise | T1027.007 | Dynamic API ResolutionSub-technique | CLAIMLOADER has utilized XOR-encrypted API names and native APIs of `LdrLoadDll()` and `LderGetProcedureAddress()` to resolve imports dynamically.[1][2] |
Groups, software, and campaigns
G0129: Mustang Panda
Mustang Panda is a China-based cyber espionage threat actor that has been conducting operations since at least 2012. Mustang Panda has been known to use tailored phishing lures and decoy documents to deliver malicious payloads. Mustang Panda has targeted government, diplomatic, and non-governmental organizations, including think tanks, religious institutions, and research entities, across the United States, Europe, and Asia, with notable activity in Russia, Mongolia, Myanmar, Pakistan, and Vietnam. [1][2][3][4][5][6][7][8][9][10][11][12][13]
All related ATT&CK context
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.
Imported snapshots across ATT&CK releases(3)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 20.0 | 1.0 | Current bundle | 290eaa8ca3bd… | ||
| 19.2 | 1.0 | Older bundle | 290eaa8ca3bd… | ||
| 19.1 | 1.0 | Older bundle | 290eaa8ca3bd… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]IBM MUSTANG PANDA PUBLOAD CLAIMLOADER JUNE 2025
Golo Muhr, Joshua Chung. (2025, June 23). Hive0154 aka Mustang Panda shifts focus on Tibetan community to deploy Pubload backdoor. Retrieved August 4, 2025.
Open source URL - [2]2025_IBM_PUBLOAD_TONESHELL_HIUPAN_CLAIMLOADER_MUSTANG PANDA
Golo Muhr, Joshua Chung. (2025, May 15). Hive0154 targeting US, Philippines, Pakistan and Taiwan in suspected espionage campaign. Retrieved August 4, 2025.
Open source URL - [3]mitre-attackS1236Open source URL
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