S1249: HexEval Loader
HexEval Loader is a hex-encoded loader that collects host data, decodes follow-on scripts and acts as a downloader for the BeaverTail malware. HexEval Loader was first reported in April 2025. HexEval Loader has previously been leveraged by North Korea-affiliated threat actors identified as Contagious Interview. HexEval Loader has been delivered to victims through code repository sites utilizing typosquatting naming conventions of various npm packages.[1][2][3]
Security context for executives and security teams
S1249: HexEval Loader describes [HexEval Loader](https://attack.mitre.org/software/S1249) is a hex-encoded loader that collects host data, decodes follow-on scripts and acts as a downloader for the [BeaverTail](https://attack.mitre.org/software/S1246) malware. [HexEval Loader](https://attack.mitre.org/software/S1249) was first reported in April 2025. [HexEval Loader](https://attack.mitre.org/software/S1249) has previously been leveraged by North Korea-affiliated threat actors identified as [Contagious Interview](https://attack.mitre.org/groups/G1...
Executive priority
S1249: HexEval Loader 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 S1249: HexEval Loader by reviewing the official ATT&CK relationships, mapped tactics (the mapped ATT&CK tactic context), supported platforms (Linux, macOS, 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 S1249: HexEval Loader 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.
HexEval Loader
HexEval Loader is a hex-encoded loader that collects host data, decodes follow-on scripts and acts as a downloader for the BeaverTail malware. HexEval Loader was first reported in April 2025. HexEval Loader has previously been leveraged by North Korea-affiliated threat actors identified as Contagious Interview. HexEval Loader has been delivered to victims through code repository sites utilizing typosquatting naming conventions of various npm packages.[1][2][3]
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 | T1082 | System Information Discovery | HexEval Loader has identified the OS and MAC address of victim device through host fingerprinting scripting.[3] |
| Enterprise | T1056.001 | KeyloggingSub-technique | HexEval Loader has utilized a cross-platform keylogger that has the capability to capture keystrokes on Windows, macOS and Linux systems.[3] |
| Enterprise | T1105 | Ingress Tool Transfer | HexEval Loader has been used to download a malicious payload to include BeaverTail.[1][2][3] |
| Enterprise | T1059.007 | JavaScriptSub-technique | HexEval Loader has executed malicious JavaScript code.[1][3] |
| Enterprise | T1027.013 | Encrypted/Encoded FileSub-technique | HexEval Loader has encoded module names and C2 URLs as hexadecimal strings in attempts to evade analysis.[1][3] |
| Enterprise | T1016 | System Network Configuration Discovery | HexEval Loader has leveraged server-side client configurations to identify the public IP of the victim host.[3] |
| Enterprise | T1041 | Exfiltration Over C2 Channel | HexEval Loader has exfiltrated victim data using HTTPS POST requests to its C2 servers.[1][3] |
| Enterprise | T1036.005 | Match Legitimate Resource Name or LocationSub-technique | HexEval Loader has masqueraded and typosquatted as legitimate code repository packages and projects.[1][3] |
| Enterprise | T1033 | System Owner/User Discovery | HexEval Loader has collected the username from the victim host.[3] |
| Enterprise | T1614 | System Location Discovery | HexEval Loader has a function where the C2 endpoint can identify the geographical location of a victim host based on request headers, execution environment and runtime conditions.[3] |
| Enterprise | T1071.001 | Web ProtocolsSub-technique | HexEval Loader has used HTTP and HTTPS POST requests to communicate with C2.[1][2][3] |
| Enterprise | T1140 | Deobfuscate/Decode Files or Information | HexEval Loader has decoded its payload prior to execution.[1][2][3] |
Groups, software, and campaigns
G1052: Contagious Interview
Contagious Interview is a North Korea–aligned threat group active since 2023. The group conducts both cyberespionage and financially motivated operations, including the theft of cryptocurrency and user credentials. Contagious Interview targets Windows, Linux, and macOS systems, with a particular focus on individuals engaged in software development and cryptocurrency-related activities. [1][2][3][4][5][6][7][8]
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 | 1.0 | Current bundle | 44c1b09bab54… | ||
| 19.1 | 1.0 | Older bundle | 44c1b09bab54… |
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]Socket Contagious Interview NPM April 2025
Kirill Boychenko. (2025, April 4). Lazarus Expands Malicious npm Campaign: 11 New Packages Add Malware Loaders and Bitbucket Payloads. Retrieved October 20, 2025.
Open source URL - [2]Socket BeaverTail XORIndex HexEval Contagious Interview July 2025
Kirill Boychenko. (2025, July 14). Contagious Interview Campaign Escalates With 67 Malicious npm Packages and New Malware Loader. Retrieved October 19, 2025.
Open source URL - [3]Socket HexEval BeaverTail Contagious Interview June 2025
Kirill Boychenko. (2025, June 25). Another Wave: North Korean Contagious Interview Campaign Drops 35 New Malicious npm Packages. Retrieved October 19, 2025.
Open source URL - [4]mitre-attackS1249Open source URL
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