H3XA — Operational Evidence

TypeMalware

External ID—

First seen2026-08-14

Last seen2026-08-14

Confidence

—

[RainyDay](https://attack.mitre.org/software/S0629) is a backdoor tool that has been used by [Naikon](https://attack.mitre.org/groups/G0019) since at least 2020.(Citation: Bitdefender Naikon April 2021)

Labels

malware

26 recorded

Relationships

uses

from Naikon

Group

uses

to Credentials from Web Browsers

Technique

uses

to Data from Local System

Technique

uses

to Deobfuscate/Decode Files or Information

Technique

uses

to DLL

Technique

uses

to Encrypted/Encoded File

Technique

uses

to Exfiltration to Cloud Storage

Technique

uses

to Fallback Channels

Technique

uses

to File and Directory Discovery

Technique

uses

to File Deletion

Technique

uses

to Ingress Tool Transfer

Technique

uses

to Local Data Staging

Technique

uses

to Masquerade Task or Service

Technique

uses

to Match Legitimate Resource Name or Location

Technique

uses

to Native API

Technique

uses

to Non-Application Layer Protocol

Technique

uses

to Process Discovery

Technique

uses

to Proxy

Technique

uses

to Scheduled Task

Technique

uses

to Screen Capture

Technique

uses

to Symmetric Cryptography

Technique

uses

to System Service Discovery

Technique

uses

to Web Protocols

Technique

uses

to Windows Command Shell

Technique

uses

to Windows Credential Manager

Technique

uses

to Windows Service

Technique

2 external

References

mitre-attack

S0629

open

Bitdefender Naikon April 2021

https://www.bitdefender.com/files/News/CaseStudies/study/396/Bitdefender-PR-Whitepaper-NAIKON-creat5397-en-EN.pdf

open