Kimsuky

Kimsuky is a Democratic People's Republic of Korea (DPRK)-based cyber espionage group that has been active since at least 2012. The group initially targeted South Korean government agencies, think tanks, and subject-matter experts in various fields. Its operations expanded to include the United Nations and organizations in the government, education, business services, and manufacturing sectors across the United States, Japan, Russia, and Europe. Kimsuky has focused collection on foreign policy and national security issues tied to the Korean Peninsula, nuclear policy, and sanctions. Kimsuky operations have overlapped with those of other North Korean state-sponsored cyber espionage actors as a result of ad hoc collaborations or other limited resource sharing.¹²³⁴⁵⁶ Kimsuky was assessed to be responsible for the 2014 Korea Hydro & Nuclear Power Co. compromise; other notable campaigns include Operation STOLEN PENCIL (2018), Operation Kabar Cobra (2019), and Operation Smoke Screen (2019).⁷⁸⁹ In 2023, Kimsuky was observed using commercial large language models (LLMs) to assist with vulnerability research, scripting, social engineering and reconnaissance.¹⁰ DPRK threat actor cluster boundaries overlap in open source reporting, with some security researchers consolidating all attributed North Korean state-sponsored cyber activity under Lazarus Group, rather than tracking operationally distinct subgroups.

1. EST Kimsuky April 2019
2. Cybereason Kimsuky November 2020
3. Malwarebytes Kimsuky June 2021
4. CISA AA20-301A Kimsuky
5. Mandiant APT43 March 2024
6. Proofpoint TA427 April 2024
7. Netscout Stolen Pencil Dec 2018
8. EST Kimsuky SmokeScreen April 2019
9. AhnLab Kimsuky Kabar Cobra Feb 2019
10. MSFT-AI

Claims and citations

Every claim comes from a writer; provenance is the writer's assertion, not a review verdict from this directory. Validity reads by citation year.

Technique use

Aliases

APT43 · Black Banshee · Earth Kumiho · Emerald Sleet · Kimsuky · PatheticSlug · Springtail · TA427 · THALLIUM · Velvet Chollima

Reading and review

Records are auto-ingested and not human-reviewed. Confidence is the writer's 0–100 value; bands split at ≥80 / 50–79 / <50 into high / medium / low. The four trust axes (synthetic, lifecycle, band, source count) stay separate and never merge into one score.

Corrections