S0275: UPPERCUT
UPPERCUT is a 32-bit HTTP-based backdoor that has been used by menuPass since at least 2017.[1] Once thought to be exclusive to menuPass, UPPERCUT was also observed being used by menuPass-associated MirrorFace during Operation AkaiRyū.[2]
Security context for executives and security teams
S0275: UPPERCUT describes [UPPERCUT](https://attack.mitre.org/software/S0275) is a 32-bit HTTP-based backdoor that has been used by [menuPass](https://attack.mitre.org/groups/G0045) since at least 2017.(Citation: FireEye APT10 Sept 2018) Once thought to be exclusive to [menuPass](https://attack.mitre.org/groups/G0045), [UPPERCUT](https://attack.mitre.org/software/S0275) was also observed being used by [menuPass](https://attack.mitre.org/groups/G0045)-associated [MirrorFace](https://attack.mitre.org/groups/G1054) during [Operation AkaiRyū](h...
Executive priority
S0275: UPPERCUT 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 S0275: UPPERCUT 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 S0275: UPPERCUT 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.
UPPERCUT
UPPERCUT is a 32-bit HTTP-based backdoor that has been used by menuPass since at least 2017.[1] Once thought to be exclusive to menuPass, UPPERCUT was also observed being used by menuPass-associated MirrorFace during Operation AkaiRyū.[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 | T1071.001 | Web ProtocolsSub-technique | |
| Enterprise | T1124 | System Time Discovery | |
| Enterprise | T1033 | System Owner/User Discovery | |
| Enterprise | T1059.003 | Windows Command ShellSub-technique | |
| Enterprise | T1574.001 | DLLSub-technique | UPPERCUT has been sideloaded through a legitimately signed application from the JustSystems Corporation.CitationESET MirrorFace 2025 |
| Enterprise | T1113 | Screen Capture | |
| Enterprise | T1573.001 | Symmetric CryptographySub-technique | Some versions of UPPERCUT have used the hard-coded string “this is the encrypt key” for Blowfish encryption when communicating with a C2. Later versions have hard-coded keys uniquely for each C2 address.[1] UPPERCUT has also used custom ChaCha20, XOR, and LZO algorithms for C2 communication.CitationTrend Micro Earth Kasha Updates APR 2025[2] |
| Enterprise | T1016 | System Network Configuration Discovery | |
| Enterprise | T1132.001 | Standard EncodingSub-technique | |
| Enterprise | T1082 | System Information Discovery | |
| Enterprise | T1105 | Ingress Tool Transfer | |
| Enterprise | T1548.002 | Bypass User Account ControlSub-technique | |
| Enterprise | T1005 | Data from Local System | |
| Enterprise | T1678 | Delay Execution | |
| Enterprise | T1083 | File and Directory Discovery |
Groups, software, and campaigns
G0045: menuPass
menuPass is a threat group that has been active since at least 2006. Individual members of menuPass are known to have acted in association with the Chinese Ministry of State Security's (MSS) Tianjin State Security Bureau and worked for the Huaying Haitai Science and Technology Development Company.[1][2]
menuPass has targeted healthcare, defense, aerospace, finance, maritime, biotechnology, energy, and government sectors globally, with an emphasis on Japanese organizations. In 2016 and 2017, the group is known to have targeted managed IT service providers (MSPs), manufacturing and mining companies, and a university.[3][4][5][6][7][1][2]
G1054: MirrorFace
MirrorFace is a People's Republic of China (PRC)-aligned cyberespionage actor believed to be a subgroup under the menuPass umbrella based on targeting, tools, and infrastructure overlaps. MirrorFace has been active since at least 2019, at first exclusively targeting Japanese organizations across the media, defense, diplomatic, financial, manufacturing, and academic sectors. Subsequent MirrorFace operations included targets in Central Europe and featured use of LODEINFO, HiddenFace, and UPPERCUT malware.[1][2][3][4][5][6]
C0060: Operation AkaiRyū
Operation AkaiRyū (Japanese for RedDragon) was a cyberespionage spearphishing campaign conducted by MirrorFace between June and September 2024 against entities in Japan and Central Europe. Operation AkaiRyū notably included the first reported targeting of a European entity by MirrorFace, as well as their use of UPPERCUT, which was thought to be exclusive to menuPass.[1][2]
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(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 2.0 | Current bundle | 0f3a9eab109a… | ||
| 19.1 | 2.0 | Older bundle | 0f3a9eab109a… |
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]FireEye APT10 Sept 2018
Matsuda, A., Muhammad I. (2018, September 13). APT10 Targeting Japanese Corporations Using Updated TTPs. Retrieved September 17, 2018.
Open source URL - [2]Trend Micro Earth Kasha Anel NOV 2024
Hiroaki, H. (2024, November 26). Guess Who’s Back - The Return of ANEL in the Recent Earth Kasha Spear-phishing Campaign in 2024. Retrieved April 17, 2026.
Open source URL - [3]ANEL
(Citation: FireEye APT10 Sept 2018)
- [4]UPPERCUT
(Citation: FireEye APT10 Sept 2018)
- [5]mitre-attackS0275Open 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.