FishMaster

Aliases: JollyJellyfish

First seen
2022-05-10 00:00:00
Malware type
loader
Family
Malware family
Profile updated
2026-07-07 13:02:09

Targeted industries: government-and-public-sector financial-services technology-and-telecommunications

Context

FishMaster, also known as JollyJellyfish, is a custom loader designed for deploying CobaltStrike beacons. It has been observed targeting various sensitive sectors, leveraging stealth techniques to deliver its payload.

Detection coverage

  • 1 YARA rules

Detection rules

  • MALPEDIA_Win_Fishmaster_Auto (yara-rule)

Reports & references

  • media-exp1.licdn.com — 1639591145314 (report)
  • decoded.avast.io — Backdoored Client From Mongolian Ca Monpass (report)
  • speakerdeck.com — Winnti Is Coming Evolution After Prosecution At Hitcon2021 (report)
  • malpedia.caad.fkie.fraunhofer.de — Win.Fishmaster (report)

External references