S0459: MechaFlounder
MechaFlounder is a python-based remote access tool (RAT) that has been used by APT39. The payload uses a combination of actor developed code and code snippets freely available online in development communities.[1]
Security context for executives and security teams
S0459: MechaFlounder describes [MechaFlounder](https://attack.mitre.org/software/S0459) is a python-based remote access tool (RAT) that has been used by [APT39](https://attack.mitre.org/groups/G0087). The payload uses a combination of actor developed code and code snippets freely available online in development communities.(Citation: Unit 42 MechaFlounder March 2019)
Executive priority
S0459: MechaFlounder 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 S0459: MechaFlounder 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 S0459: MechaFlounder 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.
MechaFlounder
MechaFlounder is a python-based remote access tool (RAT) that has been used by APT39. The payload uses a combination of actor developed code and code snippets freely available online in development communities.[1]
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 | T1041 | Exfiltration Over C2 Channel | MechaFlounder has the ability to send the compromised user's account name and hostname within a URL to C2.[1] |
| Enterprise | T1036.005 | Match Legitimate Resource Name or LocationSub-technique | MechaFlounder has been downloaded as a file named lsass.exe, which matches the legitimate Windows file.[1] |
| Enterprise | T1033 | System Owner/User Discovery | MechaFlounder has the ability to identify the username and hostname on a compromised host.[1] |
| Enterprise | T1132.001 | Standard EncodingSub-technique | MechaFlounder has the ability to use base16 encoded strings in C2.[1] |
| Enterprise | T1071.001 | Web ProtocolsSub-technique | MechaFlounder has the ability to use HTTP in communication with C2.[1] |
| Enterprise | T1059.003 | Windows Command ShellSub-technique | MechaFlounder has the ability to run commands on a compromised host.[1] |
| Enterprise | T1059.006 | PythonSub-technique | MechaFlounder uses a python-based payload.[1] |
| Enterprise | T1105 | Ingress Tool Transfer | MechaFlounder has the ability to upload and download files to and from a compromised host.[1] |
Groups, software, and campaigns
G0087: APT39
APT39 is one of several names for cyber espionage activity conducted by the Iranian Ministry of Intelligence and Security (MOIS) through the front company Rana Intelligence Computing since at least 2014. APT39 has primarily targeted the travel, hospitality, academic, and telecommunications industries in Iran and across Asia, Africa, Europe, and North America to track individuals and entities considered to be a threat by the MOIS.[1][2][3][4][5]
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 | Older bundle | 3c0ddda6c5e9… | ||
| 19.2 | 1.0 | Current bundle | 3c0ddda6c5e9… | ||
| 19.1 | 1.0 | Older bundle | 3c0ddda6c5e9… |
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]Unit 42 MechaFlounder March 2019
Falcone, R. (2019, March 4). New Python-Based Payload MechaFlounder Used by Chafer. Retrieved May 27, 2020.
Open source URL - [2]mitre-attackS0459Open source URL
Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.