Threadlinqs IntelligenceStart free

ATT&CK techniqueInitial Access

T1566 Phishing

Initial AccessEnterprise

As of 2026-10-05, T1566 (Phishing) appears in 641 tracked threats, first reported 2022-04-07 and most recently 2026-10-04, with linked actors including APT28, APT38, Forest Blizzard; it most often appears alongside T1027 (Obfuscated Files or Information).

Tracked threats
641101 critical, 440 high, 88 medium, 4 low
First seen
2022-04-07
Last seen
2026-10-04
Threat actors
171In the threats using it
Detection rules
314Blue tier and above

Data as of:

Activity timeline

T1566 first appeared in tracked threats on and was most recently reported on . The busiest month was 2026-07 with 215 reports, and 640 of the 641 threats were reported in the twelve months to 2026-10.

How adversaries use it

T1566 Phishing is catalogued by MITRE ATT&CK under the Initial Access tactic in the Enterprise matrix. Threadlinqs maps 641 of 2623 tracked threats (24.4%) to it; by severity that is 101 critical, 440 high, 88 medium, 4 low.

Threats that use T1566 most often also use T1027 Obfuscated Files or Information (400 threats), T1071 Application Layer Protocol (364 threats), T1204 User Execution (362 threats), T1059 Command and Scripting Interpreter (333 threats), T1005 Data from Local System (327 threats). These are the techniques an intrusion set tends to chain with it, so they are the natural next places to look when it is observed.

171 tracked threat actors appear in the threats that use T1566; the most frequent are APT28 (15), APT38 (13), Forest Blizzard (13), MuddyWater (13), Contagious Interview (12).

Mitigations

MITRE ATT&CK lists 6 mitigations for T1566.

Data sources

Telemetry that can reveal T1566, per MITRE ATT&CK.

  • Application Log — Application Log Content
  • File — File Creation
  • Network Traffic — Network Traffic Content, Network Traffic Flow

Threat actors using it

Tracked threats

The 30 most recent of 641 tracked threats that use T1566.

Detection coverage

Threadlinqs maintains 314 detection rules mapped to T1566 (SPL 111, KQL 101, Sigma 102). Rule content is available to Blue tier accounts and above; this page shows counts only.

314 detection rules (SPL/KQL/Sigma) · Blue and above. Compare plans

Sub-techniques