Threat intelligence / Malware

GuLoader

[GuLoader](https://attack.mitre.org/software/S0561) is a file downloader that has been used since at least December 2019 to distribute a variety of remote administration tool (RAT) malware, including [NETWIRE](https://attack.mitre.org/software/S0198), [Agent Tesla](https://attack.mitre.org/software/S0331), [NanoCore](https://attack.mitre.org/software/S0336), FormBook, and Parallax RAT.(Citation: Unit 42 NETWIRE April 2020)(Citation: Medium Eli Salem GuLoader April 2021)

Malware

TypeMalware

External ID—

First seen2026-08-14

Last seen2026-08-14

Confidence

—

[GuLoader](https://attack.mitre.org/software/S0561) is a file downloader that has been used since at least December 2019 to distribute a variety of remote administration tool (RAT) malware, including [NETWIRE](https://attack.mitre.org/software/S0198), [Agent Tesla](https://attack.mitre.org/software/S0331), [NanoCore](https://attack.mitre.org/software/S0336), FormBook, and Parallax RAT.(Citation: Unit 42 NETWIRE April 2020)(Citation: Medium Eli Salem GuLoader April 2021)

Labels

malware

12 recorded

Relationships

uses

to File Deletion

Technique

uses

to Ingress Tool Transfer

Technique

uses

to Malicious File

Technique

uses

to Malicious Link

Technique

uses

Technique

uses

to Process Injection

Technique

uses

to Registry Run Keys / Startup Folder

Technique

uses

to Spearphishing Link

Technique

uses

to System Checks

Technique

uses

to Time Based Checks

Technique

uses

to Web Protocols

Technique

uses

Technique

3 external

References

mitre-attack

S0561

Unit 42 NETWIRE April 2020

https://unit42.paloaltonetworks.com/guloader-installing-netwire-rat/

Medium Eli Salem GuLoader April 2021

https://elis531989.medium.com/dancing-with-shellcodes-cracking-the-latest-version-of-guloader-75083fb15cb4