D
CyberUnattributed

Poseidon Group

Cybercriminal groupTrackedPending verification
CyberUNK
Identification silhouette. Not drawn to scale between entries.
Fact cardConfidence · Source
System
TypeCybercriminal group
ProliferationOrigin country only
Active since2005At least 2005Med[1]
MITRE ATT&CK IDG0033High[1]
Capabilities
ATT&CK techniques used8ATT&CK v20.1High[1]
Attribution and activity
Attributed sponsorPortuguese-speaking groupMed[1]
Notes
Poseidon Group is a Portuguese-speaking threat group that has been active since at least 2005. The group has a history of using information exfiltrated from victims to blackmail victim companies into contracting the Poseidon Group as a security firm. Description adapted from MITRE ATT&CK®, © The MITRE Corporation, used under the ATT&CK Terms of Use.
Summary

Poseidon Group is a Portuguese-speaking threat group that has been active since at least 2005. The group has a history of using information exfiltrated from victims to blackmail victim companies into contracting the Poseidon Group as a security firm.

Draft entry. Values come from the cited public sources and are awaiting editor verification.
CompareJSON
Operators
Sources
  1. Poseidon Group, Group G0033, MITRE ATT&CK
    Published/updated 2026-07-31 · Tier 2 · checked 2026-11-08
Change log
  • 2026-11-08 Entry created from MITRE ATT&CK Enterprise v20.1 (group G0033)