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MITRE ATT&CK® Malware

S0134: Downdelph

Downdelph is a first-stage downloader written in Delphi that has been used by APT28 in rare instances between 2013 and 2015. [1]

EnterpriseS0134MalwareObject v1.2Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

S0134: Downdelph describes [Downdelph](https://attack.mitre.org/software/S0134) is a first-stage downloader written in Delphi that has been used by [APT28](https://attack.mitre.org/groups/G0007) in rare instances between 2013 and 2015. (Citation: ESET Sednit Part 3)

Executive priority

S0134: Downdelph 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 S0134: Downdelph 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 S0134: Downdelph 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.

Official MITRE ATT&CK definition

Downdelph

Downdelph is a first-stage downloader written in Delphi that has been used by APT28 in rare instances between 2013 and 2015. [1]

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

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.

ATT&CK relationship table

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.

5 rows
DomainIDNameRelationship / procedure
EnterpriseT1001.001Junk DataSub-technique

Downdelph inserts pseudo-random characters between each original character during encoding of C2 network requests, making it difficult to write signatures on them.[1]

EnterpriseT1548.002Bypass User Account ControlSub-technique

Downdelph bypasses UAC to escalate privileges by using a custom “RedirectEXE” shim database.[1]

EnterpriseT1573.001Symmetric CryptographySub-technique

Downdelph uses RC4 to encrypt C2 responses.[1]

EnterpriseT1105Ingress Tool Transfer

After downloading its main config file, Downdelph downloads multiple payloads from C2 servers.[1]

EnterpriseT1574.001DLLSub-technique

Downdelph uses search order hijacking of the Windows executable sysprep.exe to escalate privileges.[1]

Associated objects

Groups, software, and campaigns

GroupEnterprise

G0007: APT28

APT28 is a threat group that has been attributed to Russia's General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS) military unit 26165.[1][2] This group has been active since at least 2004.[3][4][5][6][7][8][9][10][11][12][13]

APT28 reportedly compromised the Hillary Clinton campaign, the Democratic National Committee, and the Democratic Congressional Campaign Committee in 2016 in an attempt to interfere with the U.S. presidential election.[5] In 2018, the US indicted five GRU Unit 26165 officers associated with APT28 for cyber operations (including close-access operations) conducted between 2014 and 2018 against the World Anti-Doping Agency (WADA), the US Anti-Doping Agency, a US nuclear facility, the Organization for the Prohibition of Chemical Weapons (OPCW), the Spiez Swiss Chemicals Laboratory, and other organizations.[14] Some of these were conducted with the assistance of GRU Unit 74455, which is also referred to as Sandworm Team.

Relationship explorer

All related ATT&CK context

Change history

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.

ATT&CK release
19.2
Object version
1.2
Created
Modified
Raw hash
764a0d9692f30342...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.21.2Current bundle764a0d9692f3…
19.11.2Older bundle764a0d9692f3…
Raw source

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.

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    ESET Sednit Part 3

    ESET. (2016, October). En Route with Sednit - Part 3: A Mysterious Downloader. Retrieved November 21, 2016.

  2. [2]
    mitre-attackS0134
    Open source URL
Source and licensing

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.