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MITRE ATT&CK® Malware

S1104: SLOWPULSE

SLOWPULSE is a malware that was used by APT5 as early as 2020 including against U.S. Defense Industrial Base (DIB) companies. SLOWPULSE has several variants and can modify legitimate Pulse Secure VPN files in order to log credentials and bypass single and two-factor authentication flows.[1]

EnterpriseS1104MalwareObject v1.1Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

S1104: SLOWPULSE describes [SLOWPULSE](https://attack.mitre.org/software/S1104) is a malware that was used by [APT5](https://attack.mitre.org/groups/G1023) as early as 2020 including against U.S. Defense Industrial Base (DIB) companies. [SLOWPULSE](https://attack.mitre.org/software/S1104) has several variants and can modify legitimate Pulse Secure VPN files in order to log credentials and bypass single and two-factor authentication flows.(Citation: Mandiant Pulse Secure Zero-Day April 2021)

Executive priority

S1104: SLOWPULSE 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 S1104: SLOWPULSE by reviewing the official ATT&CK relationships, mapped tactics (the mapped ATT&CK tactic context), supported platforms (Network Devices), 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 S1104: SLOWPULSE 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

SLOWPULSE

SLOWPULSE is a malware that was used by APT5 as early as 2020 including against U.S. Defense Industrial Base (DIB) companies. SLOWPULSE has several variants and can modify legitimate Pulse Secure VPN files in order to log credentials and bypass single and two-factor authentication flows.[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.

6 rows
DomainIDNameRelationship / procedure
EnterpriseT1556.004Network Device AuthenticationSub-technique

SLOWPULSE can modify LDAP and two factor authentication flows by inspecting login credentials and forcing successful authentication if the provided password matches a chosen backdoor password.[1]

EnterpriseT1111Multi-Factor Authentication Interception

SLOWPULSE can log credentials on compromised Pulse Secure VPNs during the `DSAuth::AceAuthServer::checkUsernamePassword`ACE-2FA authentication procedure.[1]

EnterpriseT1556.006Multi-Factor AuthenticationSub-technique

SLOWPULSE can insert malicious logic to bypass RADIUS and ACE two factor authentication (2FA) flows if a designated attacker-supplied password is provided.[1]

EnterpriseT1074.001Local Data StagingSub-technique

SLOWPULSE can write logged ACE credentials to `/home/perl/PAUS.pm` in append mode, using the format string `%s:%s\n`.[1]

EnterpriseT1554Compromise Host Software Binary

SLOWPULSE is applied in compromised environments through modifications to legitimate Pulse Secure files.CitationMandiant Pulse Secure Update May 2021

EnterpriseT1027Obfuscated Files or Information

SLOWPULSE can hide malicious code in the padding regions between legitimate functions in the Pulse Secure `libdsplibs.so` file.[1]

Associated objects

Groups, software, and campaigns

GroupEnterprise

G1023: APT5

APT5 is a China-based espionage actor that has been active since at least 2007 primarily targeting the telecommunications, aerospace, and defense industries throughout the U.S., Europe, and Asia. APT5 has displayed advanced tradecraft and significant interest in compromising networking devices and their underlying software including through the use of zero-day exploits.[1][2][3][4][5][6]

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
1.1
Created
Modified
Raw hash
8b1c5c7094900002...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.21.1Current bundle8b1c5c709490…
19.11.1Older bundle8b1c5c709490…
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]
    Mandiant Pulse Secure Zero-Day April 2021

    Perez, D. et al. (2021, April 20). Check Your Pulse: Suspected APT Actors Leverage Authentication Bypass Techniques and Pulse Secure Zero-Day. Retrieved February 5, 2024.

    Open source URL
  2. [2]
    mitre-attackS1104
    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.