MALTEIRO
G1026
BRAZIL
APT
Threat IntelligenceAPTApril 24, 2025

Malteiro Threat Profile

Brazilian threat group distributing banking trojans targeting Latin American financial institutions through malspam campaigns.

Brazilian threat group distributing banking trojans targeting Latin American financial institutions through malspam campaigns. This profile is mapped to MITRE ATT&CK G1026 and covers attribution, tooling, targeting, and defensive recommendations based on observed campaigns.

Overview & Attribution

Malteiro (also tracked as None publicly documented) is a threat group attributed to Brazil. The group primarily targets Latin American banking, financial for intelligence collection and operational objectives aligned with state interests.

MITRE ATT&CK Reference

This group is tracked as G1026 in the MITRE ATT&CK framework. All techniques referenced in this report are mapped to ATT&CK for consistent threat modeling and detection engineering.

Arsenal & Tools

Known tools and malware associated with Malteiro include:

Targeting & Operations

Malteiro operations focus on Latin American banking, financial. The group typically gains initial access through spear-phishing, exploitation of public-facing applications, or strategic web compromises before deploying custom implants for persistent access and data exfiltration.

Targeting Advisory

Organizations in the Latin American banking sector should treat Malteiro as a relevant threat and validate their detection coverage against the MITRE ATT&CK techniques listed below.

MITRE ATT&CK Mapping

Key techniques observed in Malteiro operations:

Technique IDTechnique NameTactical Context
T1566.001T1566.001Observed in Malteiro campaigns
T1204.002T1204.002Observed in Malteiro campaigns
T1059.001T1059.001Observed in Malteiro campaigns
T1185T1185Observed in Malteiro campaigns

Full ATT&CK mapping: https://attack.mitre.org/groups/G1026/

Notable Campaigns

This threat group has been active in operations targeting Latin American banking, financial. Security researchers have documented campaigns involving Mekotio and other tools deployed against organizations in multiple countries. Attribution confidence varies by campaign, but consistent infrastructure and TTP overlap links activity to Brazil-nexus operations.

Detection & Defense

Recommended defensive measures against Malteiro:

How Mjolnir Security Can Help

Defend Against Malteiro

Mjolnir Security provides tailored threat intelligence, detection engineering, and incident response services to help organizations defend against Brazil-nexus threat actors.

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Contact us: mjolnirsecurity.com

Written by: Mjolnir Security  |  Published: April 24, 2025